Joint EtMo-RussIan Ufological Expedition

ECOLOGICAL AND FAUNIST1C

STUDIES IN ETHIOPIA

PART 2 © JERBE, 2000 All Rights Reserved. This Book, or any parts thereof, may not be reproduced in any form without permission of the authors.

Prepared for publishing by A. Darkov and Kidanemariam Jembere

Printed by ESTC in Addis Ababa, Ethiopia i. • -.•■v CONTENTS v m t f c s ....— ...... - 3

INSECT FAUNA OP THE BARO-AKOBO INTERFLUVE AND ITS PRACTICAL SIGNIFICANCE ...... 6 Overview of Major Systematic Group^...... 7 Major Entomological Complexes and Their Association With Biotopes....12 Some Ecological Peculiarities...... 15 Economic Significance of Insects...... 18

SOIL ANIMAL POPULATION OF NATURAL AND ANTHROPOGENIC ECOSYSTEMS OF THE BARO-AKOBO INTERFLUVE...... 24 Testing plots...... '...... * ...... 26 Savanna c e n o s i s ...... 26 Agrocenosis :...... *...... 27 Soil animal population of savanna in the dry season...... 28 Animal populatipn of xerophytic forest on ferralitic soils...... 31 Animal population of xerophytic forest on brown siallitic savanna soils...... 32 Animal population of a high-grass gramineous grassland on brown siallitic savanna soils...... 32 Animal population on black tropical soils (dark vertisols)...... 33 Animal population of a gramineous grassland on black tropical soils (dark vertisols)...... -33 Soil animal population of savanna in the wet season (October, 1987)...... 34 • Soil animal population of agricultural lands...... 37

SOIL FAUNA OF THE DRY SAVANNA AND AGROCENOSES OF ; ; THE ABYSSINIAN UPLAND OF ETHIOPIA...... 50 Introduction...... 50 Research region, material and methods...... 52 Results...... ,...... 55 Discussion and conclusion...... 59

VISCERAL LEISHMANIASIS IN ETHIOPIA AND ITS POSSIBLE NOSOAREA CHANGES ...... 63 TERMITES AND THEIR INFLUENCE ON SOIL COVER FORMATION IN BARO-AKDBO INTERFLUVE ...... ____ . 80 Materials and methods...... - ...... 81 Results...... >85.

SOIL COVER OF THE RARO-AKOBO INTERFLUVE.... ■...... 95 •V * * - X J ■» *• *' ^ ECTOPARASITES OF SMALL MAMMALS IN THE CENTRAL PART OF BARQ-AKQBO INTERFLUVE...... Ill I. Gamasidae mites...... *...... ,.'...116 II. Ixodidae ticks...... 122 III. Fleas...... 125

.ONGHONR BEETLES (COLEOPTERA, CERAMBYCIDAE) COLLECTIONS IN SOUTH-WESTERN ETHIOPIA...... 131 THE SUBFAMILY PRIONINAE...... 131 THE SUBFAMILY CERAMBYCINAE...... '...... 132 THE SUBFAMILY LAMIINAE...... 134

ON THE RHOPALOCERA (LEPIDOPTERA) FAUNA OF SOUTH-WESTERN ETHIOPIA...... '...... 136 THE FAMILY PAPILIONIDAE...... i...... -...136 THE FAMILY PIERIDAE...... 138 THE FAMILY ACRAEIDAE...... 141 THE FAMILY DANAIDAE...... •..... 143 THE FAMILY SATYRIDAE...... 143 THE FAMILY NYMPHALIDAE...... 144 THE FAMILY LIBYTHEIDAE...... v...... 149 THE FAMILY LYCAENI0AE...... 149

NEW LARVAE OF LEAF BEETLES (COLEOPTERA, • CHR YSOMELI DAE) FROM SOTH-WEST ETHIOPIA...... 154

HYDROBIOLOGICAL EVALUATION OF THE ALVERO RIVER AND TATA LAKE...... '...... 167 Results...... 167' The stomach contents of fishes...... 112 Conclusions...... 173 Acknowledgements...... 175 PREFACE

Ethiopia is endowed with rich diversity of natural resources. The country has wide varieties of climate, soil, vegetation and wildlife. However, more than half of its available lands suffer from shortage of water. In addressing this problem, studies on the possibility of agricultural development in drought-prone areas through construction of irrigation schemes were undertaken in Ethiopia

In the eightieth such works were carried oi.r in Ethiopia with participation of experts from the former Soviet Unon (Russia). The integrated study of water and land resources in geneiai and development of irrigation scheme in particular was conducted in Gambella region South- West Ethiopia, Baro-Akobo interfluve (now Gambella National Regional State).

Most of the authors of this issue participated in the development of measures for protection and rational use of biological resources of the above mentioned territory, and in prevention and minimization of negative environmental aspects of agricultural activity.

Ecological ana faunistic studies of various groups of invertebrate animals in the area of prospective agricultural development were executed in November, 1986 - March, 1987 and in October - November, 1987. Besides, in this book the data on comparative study of soil fauna of some ecocenoses of Ethiopian Highland are also included in this book.

3 Despite the fact that some part of the region has already been used for agricultural purposes (fields, pastures), high diversity of natural vegetation as well as wildlife fauna are present

More detailed characteristics of separate groups of invertebrate animals are described in the present collection of papers, where the concrete aspects of their ecology, biology and systematics are given

The book provides a comprehensive report of series of publications of the Joint Ethio-Russian Biological Expedition (JERBE) which is carrying out scientific research in the territory of Ethiopia according to the Agreement between ‘he Ethiopian Science and Technology Commission and the Soviet/Russian Academy of Sciences, signed in January 17th, 1987.

For additional information on fauna of other groups of animals living within the Baro-Akobo interfluve, it is recommended to refer to the JE R B E ’s publications: “An Artificial Key to Fish Species of the Gambella Region" (1995 ) and “Ecological and Faunistic Studies in Ethiopia - Part 1 - fauna, ecology and systematics of vertebrates" (1997) as well as to many scientific papers in international journals.

The information included in this publication is belivered to be useful for the scientists engaged in biology, ecology and protection of the environment, especially in African countries

4 All remarks concerning the contents of the present papers, additions and comments to subjects discussed in the book, please direct to the address of the Joint Ethio-Russian Biological Expedition (JERBE): P.O. Box 2490, Addis Ababa, Ethiopia.

(Editorial Board)

5 INSECT FAUNA OF THE BARO-AKOBO INTERFLUVE AND ITS PRACTICAL SIGNIFICANCE

Medvedev L.M.

Ethiopian entomofauna is studied quite inadequately even as compared to the neighboring African countries. This is particularly true for hilly and lowland areas. Nothing is known about the structure of entomological complexes, their biotopic distribution, preimaginal stages, and ecology and phenology of species, even those which are of great practical interest. The identification most groups of Ethiopian insect fauna is presently associated with rather great difficulties. Meanwhile, studying Ethiopian entomofauna is not only of general scientific, but also of great practical significance, ;n view of the intensive development of new agricultural lands which is related to plant protection issues.

In November-December 1986, we carried out an entomological survey of a territory near the city of Gambela and the town of Abobo (the Baro-Akobo interfluve, Illubabor Administrative District, South-West Ethiopia) where a broad-scale construction of irrigation system and agricultural development of virgin land were planned. The survey was aimed at studying a general insect fauna composition, its biotopic distribution, major agricultural dominants ind pests, ecology, tropic relations, and preimaginal stages of basic species. Based on the above, an attempt was made to establish the existing structure of entomological complexes and work out a preliminary prediction of its possible change under conditions of the proposed agricultural development.

6 Short duration of our field exercises, were besides carried out in the dry season, complicated the task posed. Nevertheless, we succeeded in obtaining quite abundant information on a number of insect groups. One should emphasize a special importance of the faunal lists of leading insect groups since it is these lists that form the required basis for future solution of the majority of applied problems. Processing of materials collected allowed to make up the lists for Cerambycidae, Meloidae and Rhopalocera (see articles in the present book); data on Orthoptera, Hemiptera and Coleoptera are being finalized.

Overview of Major Systematic Groups

Orthoptera are one of the most important elements of the entomofauna of the region. This group, which is clearly dominant here both in biomass and biocenotic significance, is noted for species diversity and has an exceptional practical significance. Acrididae are of special importance. A preliminary assessment indicates that Acrididae are represented here by no less than 100 species, about 20 of which are dominant or mass ones; these are mostly large forms. Practically all of them are polyphagous phytophagans, which prefer grasses provided they have choice. Acrididae are generally attracted by arid habitats. As for small-sized locusts, one should mention typical Tetrigidae noted for their high numbers and species abundance. On the whole the density of the locusts varies within a broad range, however, acceptance samplings carried out predominantly In the high-grass savanna revealed from 6-8 to 40-50 individuals per 1 m2 which mainly belonged to large species.

7 Gryllidae are also abundant though less than Acrididae. These are mainly nighttime and latent forms which were caught using light sources. Altogether about 30 species were registered, 4-5 of which were the mass ones. One should specially mention Gryllotalpidae (2-3 species) which are attracted by light soils. Tettigoniidae, being a more mesophillic group, are impoverished.

Among orders closely related to Orthoptera one should note Blattodea and Mantodea. The former are mostly represented by small-sized forms whose numbers are not very high; the latter are dominated by a few common species which are not abundant either. Termites (Isoptera), which are the most important tropical group, can compete with Orthoptera in numbers and, possibly, in biomass though we failed to carry out special surveys requiring specific methodology. Two major ecological subgroups can be noted among them - geobionts nesting in soil which are abundant In all soil samples, and xylobionts which construct high conic termitariums around dead tree trunks (a typical feature of the local landscape). Some termitariums are several meters high. Xylophlllc termites of the East African savanna play the leading role in dead wood processing and Its further involvement in the cycle of matter. Soll-dwdiing forms take an active part in soil formation processes, but damage the roots of some agricultural crops.

As for the order Homoptera, one cannot help noting the abundance of Coccidae and Diaspididae, and an almost complete absence of Aphididae (maybe only in the dry period). Cicadidae are quite common and are represented by small-sized forms in the savanna and predominantly large forms in forests.

0 The order Hemiptera generally seems impoverished, with a marked dominance of individual groups: plant-feeding Coreidae and bugs of the genus Aelia, which are strongly associated both with wild and cultivated grasses. Larvae and imagos feed mostly on ears inflicting a serious Injury on grains. The density of bugs in some savanna areas was titijh as 40 individuals per 1 m2, and 25-30 individuals per 1 m2 In a sorghum plantation in December.

Coleoptera are the largest order with a broad ecological range. We shall only discuss its major families, the material has not been so much the more fully identified.

Carabidae are quite scarce and were not practically encountered during the daytime collections. At night they were caught by trap-jars and flew to light. Small-sized species prevailed, mostly Agonini.

Tenebrionidae are rather numerous though they belong to just a few species of the tribe Opatrini. They were active in daytime, always caught into traps and flew to light.

Meloidae collected belong to 10 species, 6 of which are the mass ones. Daytime forms are represented by the genus Mylabris (4 species), the nighttime ones by the genera Psalydonytta and Cylindrothorax. The group has a great practical significance since it parasitizes on Acrididae.

9 Elateridae were not encountered In daytime during mowing, but a few of them flew to light; these were mainly representatives of the genus Agriotes strongly associated with agrocenose.

Cerambycidae were encountered In solitary instances; the over-whelming majority of 23 insect species collected were caught using a light sources. On the whole, capricorn beetles collected are typical of the savanna and are quite wide-spread in tropical Africa though many of the species recorded had not been registered in Ethiopia before.

Chrysomelidae received special attention, however, the total number of the species detected did not exceed 60. The dominant subfamilies include Eumospinae, GaJeruonae, AJt/c/nae, and Cassidinae, which are attracted by humid floodplain habitats. Just a few representatives of Clytrinae and Cryptocephalinae are typical of the savanna; solitary individuals of Hispinae (especially of the genus Gonophora) were encountered in tropical forests exclusively. Chrysomelidae are strongly associated with all background plants of the region, including agricultural crops; a narrow trophic specialization of the insects allows a detailed description of various types of plant communities.

As for Scarabaeidae, 65 species (belonging to 35 genera) were detected. On the whole, their fauna is typical of the savanna and similar to the Central African fauna though it is impoverished as compared^o the latter (a number of typica savanna groups are absent, in particular, the genus Popillia). The trophic groups are represented by mycetophages, saprophages, coprophages, rhizophages, xylosaprophages, and myrmecophages. Dung beetles mainly belong to the genus Aphodius (9 species), Onthophagus (10 species), and Scarabaeus (2 species). Being active in daytime, they also flew to light. One of the most common local species Onthophagus gazella is noted for being used for the introduction in Australia to process manure.

As for chafers, only Cetoniinae (8 species) were discovered in daytime during mowing. Gnathocera, which are largely encountered on grasses, are hardly likely to injure the latter (they are likely to feed on mold fungi growing on leaves). Dynastinae (9 species) and Rutelinae (8 species) dominate among other chafers (mainly nighttime and twilight ones) in terms of species diversity and numbers.

Ants prevail among Hymenoptera. Their high density allows them to act as a noticeable numbers regulator for other insects, including pests. Inspite of the fact that some of the ant species are phytophagans, they should be generally referred to useful insects.

As for chafers only Cetoniinae (8 species) were discovered in daytime during mowing. Gnathocera, which are largely encountered on grasses, are hardly likely to injure the latter (they are likely to feed on mold fungi growing on leaves). Dynastinae (9 species) and Rutelinae (8 species) dominate among other chafers (mainly nighttime and twilight ones) in terms of species diversity and numbers.

Ants prevail among Hymenoptera. Their high density allows them to act as a noticeable numbers regulator for other Insects, including pests.

11 Inspite of the fact that some of the ant species are phytophagans, they should be generally referred to useful insects.

As for other representatives of the order, we shall only name Sphecidae, which are quite common in the region under study. We collected 10 Sphecidae species. These insects paralyze Orthoptera and caterpillars on which they rear their larvae.

The order Lepidoptera is quite numerous. Among nighttime mothes, we should mention Noctuidae which are dangerous agricultural pests requiring a thorough study. In the dry season Rhopalocera are a background group similar to Orthoptera. The most diverse families Include Pieridae and Nympha'idae (over 20 species each). Altogether 87 species were discovered, among which several species were observed to come to Palearctic, e.g. Pieris napae and Vanessa cardui. The complete faunal survey of Rhopalocera is given in a separate article of the present book.

Major Entomological Complexes and Their Association With Biotopes

The dry tropical season Is quite unfavorable for the overwhelming majority of Insects, therefore It Is impossible to work out complete characteristics of entomological complexes only from observations within this period. Nevertheless, their basic features, background groups and dominants are quite clear.

The high-grass savanna is the most typical and dominant biotope of the region considered, which also has a priority practical significance. Its

12 areas differ In grass cover height (1.5-2 m, on the average) and abundance of trees (mostly Isolated ones, but sometimes forming curtains), and still it is a generally uniform and integral biotope. Its entomological complex is primarily characterized by the abundance and diversity of the locusts, • leaf-footed bugs, negro bugs of the genus Aelia, Scarabaeidae, Meloidae, Tenebrionidae, and to a less extent, Carabidae. Termitariums are an important landscape element. As for Hymenoptera, one can meet here Sphecidae parasitizing on Orthopera and caterpillars. Daytime Lepidoptera are quite abundant, but their species composition is not rich. Large groups such as Cuccuiionidae and Chrysomelidae are rather scarce here: Chrysomelidae number just about 10 species, mainly of the subfamilies Clytrinae and Cryptocephalinae. On the whole, the fauna is a mesoxerophilous one, with phytophagans dominating strongly over predators. Saprophages are scarce, coprobionts being the only exception. The general structure and species composition of this entomological complex have much in common with those of entomological complexes of other East African savannas though the complex under study is noticeably impoverished which might be related to exceptionally developed high ■ grasses suppressing many other plants. Besides, one may encounter here Individual forest-dwelling (and not just arboreal) insect species, therefore it is quite possible that the savannas of this type are relatively young (as compared to Kenyan and Tanzanian savannas) and could have occurred in the place of tropical forests destructed in the historic period.

Flood plain/meadow biotopes (small in area) are associated with water body banks and are noted for rich and diverse fauna. The related entomological complex is characterized by a drastic by a drastic decrease in the numbers and diversity of Acrididae, a noticeable increase in Tettigoniidae

13 and Gryllidae, a much greater diversity of Hemiptera (without the dominance of individual groups), and an Increase In Carabidae at the expense of. Tenebrionidae. Curculionidae and Chrysomelidae fauna Is richer than that In the savannas. The dominant subfamilies of Chrysomelidae (which number here a few tens of species) Indude Eumotpkiae, Galerudnae, AHicinae. Predatory Coleoptera are rather abundant: Staphylinidae, CantharkJae, Meiyridae, Cocdnellidae. Pleridae are markedly dominant among daytime Lepidoptera. The presence of the tsetse fly is typical for the flies. Termitariums are totally absent though termites are abundant in soils. The mesophillous and mesohygrophillous entomological complex Is characterized by a slight prevalence of phytophagans over predators, the prevalence being compensated by the abundance of Aranekia. Saprophage numbers are greater than those In the savanna, and saprophage species composition Is more diverse. The overwhelming majority of local species belong to those wide-spread over the A'rican continent, especially In the latitudinal direction, and the biotope population can be generally considered intrazonal,

I * - . * ' . . , : The collected material Indicated that the tropical forest In December, i.e. in the dry season peak, Is practically deprived of surface entomofauna. Insects abundant at that tirrte Included only daytime Lepidoptera (over 50 species) and ants. We also met small-slzed forest-dwelling species of Acrididae (mostly at the larval stage) and some Hemiptera species. Coleoptera were practically absent: we found single representatives of less than 20 species, Including 6 Chrysomelidae species. Insects did not fly to light either. However even these almost incidental findings Indicate that the entomological complex Is represented by mesophillous or mesohygrophillous species, most of them being endemic for Ethiopia. Savanna-dwelling species do not practically penetrate here. Besides typical tropical forests, we also investigated dry and light forests scattered as small islands about the savanna. Similar to the former, they proved to be almost lifeless from the entomological viewpoint. However, some of the species collected, particularly Hispinae which are trophically related to plants of the ginger family, are typical of tropical rain forests. Therefore we consider it possible to study dry and light forests not as an independent biotope, but as an extreme and irreversible degradation stage of tropical rain forests resultant from a long-term anthropogenic impact.

Some Ecological Peculiarities

Insect development and activity in the tropics is closely related to the rain season and a subsequent period when soil is humid enough and plants vegetate rapidly. This period corresponds to the mid-latitude summer. Active life of the overwhelming majority of insects ceases in the dry season: they usually fall into a lengthy diapause of use shelters, preimaginal stages of the open-living forms being absent at this time. Naturally, this mostly concerns mesophillous and mesohygrophillous species for whom the dry season is a kind of "arid winter". The scarcity of the dry season entomofauna is especially striking in forest habitats. Selected drought-requiring species (almost totally savanna-dwelling ones) remain active at this time, and their numbers may be significant. Thus, we can state that there are two drastically different phenological aspects of the entomofauna which can be further subdivided when studied in detail. The short-teim occurrence of mass dusters of individual insect species can be considered a typical phenomenon. Over ten dusters of this type were detected within the period of the field activities. For instance, there were two cases of abnormally high concentrations Myiabris on a mallow bush: the total number of the beetles, as estimated visually, was 250-300 in one case apd 400-500 in another, which was about two orders of magnitude higher than their usual numbers. High concentrations of Aulacophora (600-800 individuals per 2-3 m2) and Lycus (no less than 1,000 individuals per 3-5 m2) were observed in the vast overgrowth of wild squashes. It is noteworthy that while the former spedes is trophically related to squashes and can be always found on them, the latter one is not a phytophagan at all and was not encountered In collections either prior to the above case or after it. Such dusters occur all of a sudden and persist from a few hours to two days. This poorly studied phenomenon, which has not been given a satisfactory explanation up to now, was observed earlier in Turkmenia and Mongolia. It seems to be typical of arid areas and a form of insect behaviour. Let us note that flocks of locusts also begin with super-concentr­ ations of the insects within limited areas. Maybe, mechanisms of such cluster and super-concentration occurrence are similar.

Savanna burning out in the dry season (November-December), which is a large-scale cydic phenomenon strongly Influendng the biogeocenosis, is an important feature of the high-grass savanna. A huge mass of dry grasses up to several meters high actually prevents plant vegetation. When they are burnt out, free space appears, soH is fertilized by ash, and ungulates receive a higher-quality feed (though this moment is not productive from the biogeocenological viewpoint since it regularly excludes a significant amount of biomass from its cyde). Since savanna trees have adapted to fires and possess a number of morphological adaptation mechanisms, it is evident that the periodic burning out has been taking place for several millennia and its impact on the entomological complex has a priority importance.

If ungulates and most of the other mammals can go away or hide from fire in holes, the situation is absolutely different for insects. Our observations show that insects start saving only when temperature is high enough and when fire approaches them up to distances of a few decimeters (1-2 meters during large fires). As a result, good fliers usually have time to get away from fire though with noticeable losses, all the rest die. We found up to 30-35 individuals of dead locusts within 1 m2 of freshly burnt land, 80-90% of them being at the larval stage, and up to 40-50 individuals of other insects, mainly large bugs. The figures are certainly underestimated due to calculation difficulties and methodological inadequacy; in particular, we failed to determine the number of dead small-sized insects, and it must be very high. However, even active fliers move away from fire, mainly downwind, to distances no more than 100m, and so they have to fly away again some time later as fire approaches them, and they suffer new losses. As a rule, a fire front is proceeded by enormous hordes of insects whose number cannot be determined. Big flocks of birds get together in the vicinity of the fire and catch insects in the air.

On the whole, we can state that savanna burning out results in a noticeable reduction of the numbers of most insect groups, and that the percent mortality is especially high for all open-living larvae and poor fliers.. Exceptions include the imago of Orthopter, large Hymenopter, daytime Lepidoptera, as well as woil-dwellers and xylobionts. Selected insect groups are subject to significant elimination: thus, aphids are practically absent in

17 the savanna. Fires have a greater impact on phytophagous insects and a less effect on predators, and are a powerful regulation factor for savanna insect numbers.

Economic Significance of Insects

Crops presently cultivated in the territory considered include cereals (sorghum, durra, maize sugar cane, and to less extent wheat, barley, teff), legumes (bean, pea, kidney bean, lentil, ground nut), squashes, crucifers, cotton, tobacco, papaya, banana, and sweet potato. The study conducted allowed to identify a large complex of agricultural pests.

Most numerous proved to be a group of nonspecialized polyphagous pests with the prevalence of Acrididae, including Locusta migratoria. A large amount of locusts was registered on all cereals studied, as well as on legumes and cotton; isolated individuals were observed on squashes, sweet potato and banana while there were no locusts on tobacco, crucifers and papaya. It is quite evident that Acrididae preferred grasses, the latter being first damaged in their generative organs (ears, panicles) and then in leaves and stems. The density of locusts varied significantly, but it was not generally too high since the bulk of them fed on wild grasses in the savanna.

Crickets cause about the same damage as locusts, but they prefer dicotyledons rather than monocotyledons. Since crickets are nighttime and twilight insects, we failed to register them properly; nighttime examinations with a lantern helped detect them on legumes, squashes, crucifers, cotton,

18 sweet potato, and banana. Judging by the intensity of their flying to light, the cricket numbers are rather high.

Gryllotalpidae were recorded in agrocenosis only; both imagos and larvae live in light soils and gnaw plant roots. Their numbers seem to be quite high:'we collected about 20 individuals within an hour using a light source, and 2 imagos and 3 larvae when digging out a cruciferous bush.

Darkling beetles of the tribe Opatrini are background ones both in fields and savanna. The beetles stay in the topsoil and various shelters in daytime and come out to eat the green parts of plants in twilight. Larvae, which gnaw roots, cause the greatest damage. The species composition has not been established yet (there must be 2-3 harmful species).

Elateridae which are ecologically related to them are significant agricultural pests. However, their numbers were not high while the field activities were carried out and their species composition included no more than 10 species, mostly of the genus Agriotes. The role of Elateridae in agrocenosis requires further investigation; it is not impossible that their density in the rain season is quite high.

Scarabaeidae (section Pleurosticti) include a great number of pests whose larvae live in soil and are zhizophages; imagos feed on the green parts of plants. The beetles are polyphagous, but can prehas not been finalized, we cannot give here a full list of harmful species, so we shall only note such serious pests of the subfamily Dynastinae as Heteronychus arator (and evidently 2 more species of the genus). Heterolygys metes (and 1

19 more species), Oryctes sp. and Temnorrhynchus sp. Besides, pests undoubtedly include representatives of the subfamily Rutelinae (8 species registered), Rhizotroginae (1 species), and Seridnae (5 species). It is well-known that the aforementioned Heterolygus metes was brought to Australia, Oceania and America; in America, It causes great damage to a number of cultures, in particular to sugar cane.

Blister beetles of the genus Mylabris (Meloidae) gnaw leaves and especially flowers of many plants, forming mass reproduction foci. Meloidae observed near the town of Abobo undoubtedly preferred wild mallows and cotton. Two species, M. bipartita and M. bifasciata, surpassed the others in their numbers. Since Meloidae larvae parasitize on locusts, we believe that these species should be referred to useful rather than to harmful insects.

Noctuidae are always encountered in agricultural fields and fly to light in large quantities, and their caterpillars feeding mainly on roots are found in soil samples. Their negative role is evident, however, specific most harmful species can be identified only as a result of more detailed studies.

Coreidae which were observed in large amounts on the majority of agricultural crops and on many wild plants can be referred (though with a known reservation) to polyphagous pests. However, well-based conclusions can be made only when the species composition of these bugs is established and their ecology is studied more thoroughly.

20 As for specialized pests associated with selected cultures, they were only partially identified due to the short duration of the studies. We shall consider them for different cultures.

Aelia are the most numerous and serious pests on grasses. Imagos and larvae suck juice out of leaves, stems and grains; stem damage often results in stem die-off and breaking. The numbers of these bugs are rather high (usually not less than 10 individuals per 1 m2).

Sweet potato is injured quite heavily. 6 Cassidinae species were registered on it, among which 2 Aspidomorpha species and 1 Laccoptera species were mass ones. Larvae and imagos nibble leaves quite considerably, gnawing them through. A paper by Ju. M. Zajtsev "New larvae of leaf beetles (Coleoptera, Chrysomelidae) from Ethiopia" describes larvae (bf these species unknown earlier (see the present book). Colasposoma whose larvae live in soil on roots also injure sweet potato. All the aforementioned species are also observed on wild bindweed.

Cotton is strongly damaged by Podagrica sp. The beetles skeletonize leaves, their larvae live in soii on roots. The species is also a permanent wild mallow dweller. When calculations were performed, an average of one hundred beetles was registered on a bush. Polyphagous pests constantly observed on cotton include leaf-footed bug and Mylabris.

Crucifers were observed to be inhabited by Phyllotreta, their larvae being rhizobionts. However, their numbers are not high and damage caused by them is insignificant.

21 No specialized pests were registered on papaya, we only discovered a noticeable contamination by Diaspididae. Polyphagous pests seem to avoid this culture, as well.

We should specially mention the tsetse fly, a carrier of the organism which causes a dangerous cattle disease "nagana". It can be encountered during the dry season in wet places only, especially near water bodies with stagnant or slow waters, and in waterlogged areas, ie .e at sites of larva procreation. Tsetse numbers are especially high near Damsite (20 Km east of Abobo) and Lake Tata.

To our mind, the pest complex was established in the agrocenosis due to natural savanna (Acrididae, Hemiptera, Tenebrionidae) and floodplain/meadow biocenosis (Gryllidae, Gryllotaipidae, Chrysomelidae) and has close trophic relations with natural biotope vegetation.

The forthcoming irrigation and agricultural development of the savanna will evidently lead to a rapid formation of agricultural pest complex in new agricultural fields. Most of harmful insect will be inevitably included in the forming agrocenosis due to reduced natural habitats. Besides, the increased area of agricultural fields can minimize the role of fires which, as stated above, act as an indubitable regulator of insect numbers in the savanna. Hence, a general increase in phytophagous insect biomass can be expected, including the occurrence of mass reproduction foci of certain species. This is all the more dangerous that the phytophagan biomass within the whole region of projected development is incomparably larger than the biomass of predators and parasites controlling the phytophagans. Acrididae are most dangerous in this respect since their density can increase very rapidly.

22 Structure analysis of the existing entomological complex allows a supposition that cereals will suffer the greatest damage from pests. It is quite evident that plant protection service should constantly regulate pest numbers using, in particular, biological techniques. Meloidae are very promising in this respect sifice they can regulate the numbers of Acrididae to a certain degree.

Construction of an irrigation system will inevitably increase the numbers of the tsetse fly, therefore it should be studied thoroughly in the near future as a nagana carrier in the region to be developed. Analysis of $ata obtained will allow to make a conclusion on the expedience and scale of mrtiinal husbandry development in the region. SOIL ANIMAL POPULATION OF NATURAL AND ANTHROPOGENIC ECOSYSTEMS OF THE BARO-AKOBO INTERFLUVE

Rybalov L.B.

Studies on the soil animal population have been completed by now in a number of countries of Equatorial Africa in the savanna zone. The most detailed works have been accomplished on microarthropods (Athias, 1974) at the Lamto Experimental Station in West Africa (Ivory Coast) situated in a relatively humid savanna (annual precipitation rates 1275 mm) on the whole complex of invertebrates (Athias et al., 1974), Invertebrate larvae (Girard, 1973), on earthworms (Lavelle, 1978), on termites (Josens, 1971) and ants (Levieux, 1971). Similar works, but to a lesser extent (Goffinet, 1973; 1975; Goffinet et Freson, 1972), have been conducted in savanna and sparse forests of Africa (Zaire) situated also in a relatively humid zone (1200-1500 mm of annual precipitation rates). Regular soil zoological investigations have hitherto not reached the Sahel zone, the dry African savanna. Only a single paper on the animal population of Ethiopia by A.D. Pakarzevsky (1986) has been published, who studied the soil invertebrates in the black tropical soils of Ethiopia uplands.

The aim of this work is to give brief population characteristics of the main soils of dry savanna, situated in the Baro-Akobo interfluve (Illubabor region, south-west Ethiopia).

24 One of the effective methods in sljdying soil animal population is the development of testing plots at boundaries between landscape or ecological profiles. Three main types of soils are formed on the foothill plain of the Baro-Akobo interfluve. They are: ferralitic tropical (red-brown) soils, brown siallitic savanna (brown eutrophic tropical) soils and hydromorphic black tropical soils (vertisols). The elevated relief elements are characteristic of ferralitic tropical soils; the leveled weakly iqdined territories have brown siallitic soils, and at last the depressions flooded in the rainy season have black tropical soils (vertisols)^ This sequence of interdependent soils, the soil catena, has been described from a number of regions in Africa (Duchaufour, 1965); Rozanov, Rozanova, 1982), including the Baro-Akobo interfluve (Rozanov, Chelyadnic, 1983; Sizov, this issue). We've used this range as an ecological foundation selecting the testing plots. The diversity of soil cover and hydrological conditions determine vegetation variety which is represented by xerophytic deciduous and semi-deciduous sparse forests; high-grass gramineous savanna and gramineous low-grass plots, vegetation cover successions are modified by regular fires.

The studies were conducted in November-December, 1986 (the beginning of the dry season), and in October of 1987 (the end of the wet season). Comparative studies were made on 12 expert- mental plots, 5 of which were founded on the above soil types under natural vegetation and 7 on the agricultural lands under different crops.

25 Testing plots

Savanna cenosis:

1. A deciduous (xerophytic) sparse forest of the plains on an elevated wavy watershed. Anageissus, Combretum and Ce/trs spp. dominate among the emergents. The grass cover Is partly dominated by Hyrrarhenia and Pennisetum species Gramineae partly by various Commelina, Calistegia etc, herbs. The soil Is loamy ferralltlc tropical (Fe°) on a ferralltic pan (at a depth of 20-30 cm).

2. A deciduous (xerophytic) forest of a park type on the plain. Acacia, Indlgofera spp. prevail among the trees (Lauraceae, Fabaceae families). The grass layer consists of low Gramineae as well as of Cucurbitaceae and Amaranthaceae herbs. The soil is brown siaJlltic savanna sandy loam (Be).

3. A plain high-grass gramineous grassland. Dominating species are from the genera Hyparrhenia, Andropogon, Pinnisetum. The soil is llqht loamy brown slallltic savanna (Be).

4. A forest, partially defoliated in the dry season and flooded in the wet season. A Balanites spp. and some Fabaceae are dominating the upper layer. Herbs prevail among the grasses. The soil Is typical black tropical (dark vertisol), (Vp), heavy loam.

26 5. A gramineous grassland flooded in the wet season. The main Gramineae are from the genera Ecfiinochloa, Panicum, Hyparrhenia. The soil is typical black tropical (dark vertisol), (Vp), heavy loam-

Agrocenosis:

* *. • - 6. A cotton field on brown siallitic savanna soils, (Be), state-possessed crops subject to agrotechnlcal measures.

7. A sorghum field on brown siallitic savanna soils, (Be), under traditional primitive cultivation.

8. A rice field on typical black tropical soils, (Vp), state-possessed crops.

9. A sorghum field on alluvial soils, (Al), traditional agriculture.

10. A sugar-cane field on alluvial soils, (Al), traditional agriculture.

11. A maize com field on alluvial soils, (Al), traditional agriculture.

12. A sugar-cane field on typical black tropical soils, (Vp), state-possessed crops.

13. A soya field on typical black topical soils, (Vp), state-possessed crops.

We have used hand sorting of soil samples and lines of soil traps (with 4% formailne) for collecting and counting of soil and herpethoblontic

27 invertebrates, [jach sample was 1/16 m2 in size and the depth of sampling varied depending on the depth of occurrence of the Invertebrates, In most plots amounting to 30-40 cm. In 1986 there were 6 samples per plot, In 1987 - 4 samples per plot. Soil samplings In 1986 were made on plots 1 to 8, and lines of traps set on testing plots 1-11. In 1987 the samplings were made on plots 1 to 8 and traps were exposed on plots 1-8, 12, 13. Besides an estimation of the abundance, measurements of live weight of invertebrates from the samples were conducted. Recalculations of animal numbers anc1 biomass per 1 m2 were made. The abundance and dynamic density of herpethobionts has been recalculated for 100 traps per day presented In the tables in a grade system).

Analyses of some soil physico-chemical properties of the soils on the testing plots (tab. 1) were made in the laboratory of the Baro-Akobo Project <> ' . • i by R.V.Yakimova to whnm the author expresses his gratitude.

The author received consultations on the systematics of a range of soil invertebrate groups from S.I. Golovach, L.P. Titova, N.T. Zalesskaya, Y.A. Popov, K.G. Mikhailov, T.S. Perel, V.V. Yanushev. The author is deeply grateful for their help.

Soil animal population of savanna in the dry season

Samplings in 1986 have been made before mass fires in the savanna broke out. That is why the acquired values of the numbers are higher than usual for a dry savanna (Athlas et ai., 1973; Goffinet, 1975) for many groups .• of invertebrates (tab. 2). The authors think that fires greatly affect the

28 numbers of many groups of invertebrates. However, Its decline is not instant. Our censuses made before and immediately after the fire showed that the abundance of numerous herpethobiontic groups does not decline in the burnt savanna. The abundance of both grass-inhabiting insects and of litter-dwellers is reduced. Numerous animals hide in natural crevices, roots and soils pores during the dashing fires. Besides the direct elimination of invertebrates, fires destroy grass and litter layers and increase soil temperature which promotes fast drying. The latter factor becomes critical for diminishing the invertebrate numbers in the dry season (Lavelle, 1982).

The low abundance of usual soil invertebrates: such as earthworms (fam. Eudrilidae), Lithobiomorpha centipedes, beetles (Staphylinidae), ground beetles (Tenebrionidae) is characteristic of the dry season as a whole. A considerable part of the invertebrates are found in a resting stage (eggs, pupa) or in diapause. In black tropical soils under gramineous grasslands the numbers of eggs reached 600 ex./m2 Eudrilidae, Diplopoda and most of the beetles are in diapause. Unfortunately, it is very difficult to identify the systematic position of invertebrates in the egg phase that is why the composition of the animal population is not fully defined in the dry season. There still may be found centers of invertebrates accumulation against the background of generally low abundance of macrofauna restricted to the soils which have conserved an adequate amount of moisture. One of them is vertisols. The vegetative period continued in moisted biotopes while it was almost inhibited in the others.

Soil population in the dry season is represented by all the main families Of soil-inhabiting invertebrates. However it is distributed unevenly between particular groupings. A range of the most numerous families inhabiting most

29 of the biotopes may be outlined. It consists of spiders (Salticidae, Lycosidae, Zodariidae)', Geophilomorpha (MedstxxxphaUdae) ; bugs (Lygaeidae, Cydnidae, Pentatomidae)) beetles (Carabidac - Imago, Tenebrionidae - mostly larvae) and Scarabaeidae (larvae).

A high abundance of termites Is characteristic of most of the soils: their buildings take up to 5% of savanna area. High values for this group were noted during our samplings. We have found termites and their galleries even is very hard soils (vertisols, ferralitlc on pans) up to a depth of 40-50 cm. According to Lavelle's (1982) data termites reach the first place in savanna as to their numbers and the second as to their biomass (after the earthworms). However It concerns only humid savanna with the dry season lasting 2-3 months.

In a dry savanna termites dominate both in number and boimass and play the leading role In Vhe transformation of living vegetation and dead plant residues.

The most numerous groups of herpethobionts inhabiting savanna were spiders (Lycosidae, Zodariidae, Saitiddae) and ants (Formicidae), in some biotopes - also Gryllidae, Tenebrionidae and Carabidae.

A low level abundance of the saprophagous complex deserves special attention. Regardless of the termites there were 3 ex./m2 of earthworms, 8 ex./m2 woodllce, 24 ex./m2 of Diplopoda. The percentage of saprophages to the total macrofauna biomass averaged 8-9% . Only in most humid biotopes such as gramineous grassland on vertisols this parameter reached 22% (table 3).

According to trophic types the animal population of biotopes may be assembled into three groups. 1) A group with domination of predators (forest on ferralitic soils, gramineous grassland on brown siallitic soils). 2) A group of mixotrophs (forest on brown siallitic soils). 3) A group of phytophages (forest and gramineous grassland on vertisols). Thus it is evident that the wetter the soil and the higher the biomass of the vegetating grass cover, - the greater the numbers, weight and percentage of phytophages in the animal population, and the dryer the soil, the higher the percentage of predators.

Animal population of xerophytic forest on ferralitic soils

The lowest level of the invertebrate numbers of 84 ex./m2 was registered in the beginning of the dry season for this type of soils. There are no vividly expressed dominators in ferralitic soils. The most regular encounters were: spiders (Lycosidae>, Saltiddae, ZoJariidae); Diplopoda {Spirostreptidae)-, larvae and imagos of Tenebrionidae, tribe Opartini-, larvae of Scarabaeidae, tribe Seridni. Among the herpethobionts the most numerous were ants (Formiddae); spiders (Lycosidae and Zodariidae)-, beetles (Tenebrionidae and Gryllidae (tab. 4).

31 Animal population of xerophytic forest on brown siallitic savanna $bils

The numbers of larger invertebrates is almost twice as high as in the previous biotope. It is determined by a higher level of soil moisture and the existence of a litter layer at the dates of samplings. Almost 40% of the population are restricted to the litter complex. It is represented by spiders (fam. Salticidae), Carabidae beetles, tribe Masoreini and Staphylinidae. Among the proper soil groups most marked in the numbers are the larvae of Scarabaeidae, subfamily SericJnae, 67 ex./m2. Quite numerous are also the larvae of Tenebrionidae. Among the Herpethobionts the most numerous are both Tenebrionidae, tribe Opatrini, and ants.

Animal population of a high-grass gramineous grassland on brown siallittc savanna soils

The level of abundance of invertebrates is lower than in the forest on the same soils being 107 ex./m 2 as a result of soil drying and lack of litter. The composition of the dominating families is very similar to that of the forest community: spiders (Saltiddae); Scarabaeidae (subfamilies Seridnae, Rhizotroginae)’, beetles and larvae of Tenebrionidae. Besides these groups, higher numbers were also noted for Geophilomorpha (Medstocefalidae) and for beetles fam. Anthiddae. Mass herpethobiontic groups are the same as on testing plot N2, i.e. ground beetles (Carabidae) and ants.

32 Animal population on black tropical soils (dark vertisols)

The highest general level of abundance (227 ex./m2), diversity/ relatively high quantity of saprophages (Diplopoda) and woodlice are characteristic Qf soil population of this community. The role of a favorable moisture regime of vertisols at this time of.,year seems to be decisive. Five •' *1 groups are prevailing: 1) spiders (Gnaphosidae, Saltiddae, Oxyopidae, Uloboridae, Linyphiidae); 2) Diplopoda (Spirostreptidae); 3) bugs Geotomus spp. (Cydnidae); 4) ground beetles (Egodroma spp.); 5) Scarabaeidae, tribe Seridni. Among the herpethobiontic population dominants are crickets, ants and to a lesser extent spiders (Lycosidae and Zodariidae).

Animal population of a gramineous grass/and on black tropical soils (dark vertisols)

The numbers of invertebrates are practically the same as on the 4th plot being 227 ex./m 2. The soil type and moisture regime determine the level of total invertebrates abundance. Just like in the forest, soil fauna is quite diverse in this biotope. However, the structure of the invertebrates in the gramineous grassland is distinctly different from the one under a tree canopy. The most numerous are three groups: 1) spiders (Araneidae, Saltiddae, Oxyopidae, Lycosidae)-, 2) Scarabaeidae (tribes: Aphodiini, HopUini); 3) beetles (fam. Anthicidae). Among the other groups we may note here as numerous: Eudrilidae, Lepismatidae, bugs (fam. Lygaeidae),Carabidae (tribe Tachiini), Staphylinidae, Saprophages are represented by earthworms (fam,- Eudrilidae) and woodlice. Their joint weight is 22% of the total biomass, the maximal index for the studied groupings at this time of year.. The most

33 numerous herpethobionts are the same as for black tropical soils under forests: Gryllidae, Formicidae, Aranei.

Soil animal population of savanna In the wet season (October, 1987)

Samplings performed In October 1£87 have considerably updated the data on the composition of animal population of the studied soils. The identification of the material collected In the wet season was not as detailed, so we provide here only generalized characteristics. A range of invertebrates were in the egg stage during the dry season. In the wet season, invertebrates of ail the systematic groups were active and the numbers of eggs in the soil were low. The reaction of invertebrates, inhabiting different types of soils, to increased soil humidity was different (tab. 2). Thus, the rise In numbers of invertebrates in ferralltic soils on the ferralltic pan was tenfold and the biomass grew 5 times. This increase on brown siallitic soils was 1,5-2 times respective­ ly. A 1.3 and 1.5 times decrease In the abundance and biomass respectively was noted on black tropical soils (very moist at the sampling dates). In the latter case the excess soil moisture (In the wet season these biotopes are partly flooded) inhibits the activity of many soil Invertebrates.

An increase In the total numbers of Invertebrates in ferralltic and brown siallitic savanna soils was due to numerous systematic groups (tab.2). Thus, in ferralitic soils the abundance of earthworms, spiders, Lithobiomorpha (fam. Henicopidae) bugs (fam. Cydnidae), larvae of ground beetles and Lepidoptera grew drastically. In the forest on brown siallitic soils a growth of the numbers of Isopoda, Henicopidae, Carabidae imagos, Scarabaeidae larvae, Lepidoptera larvae was noted. A coslderable growth In the abundance Is noted In gramlne-

34 ous communities on the same soils for cockroaches, Carabidae, Staphylinidae, as well as Tenebrionidae and Lepidoptera lan/ae.

Thus, the most notable rise was in the numbers of phyto- and saprophagous invertebrates, and also of surface and litter layer predators. The abundance level of many a groups inhabiting vertisols did not change in comparison with the dry season. A decline in the numbers was noted in these soils for a few groups only: in the forest those are bugs (fam. Cydnidae), ground beetles, lamellicorn beetles; in the gramineous grassland - Anthicidae imagos, Scarabaeidae larvae. The rise in the numbers of invertebrates in the ferralitic and brown siallitic soils and its decline in the black tropical soils has notably changed the dominant composition and trophic structure of animal population (tabs. 2, 3).

However, it is noteworthy that according to trophogy the studied invertebrate complexes are divided into the same three groups as in the dry season. But now the composition of each of these groups is different.. Phytophages dominate in the first one (forest on ferralitic and gramineous grassland on brown siallitic soils). In the second group (forest on brown siallitic soils) dominate mixotrophic invertebrates with a higher percentage of saprophages. In the third group (forest and gramineous grassland on vertisols) both saprophages and predators prevail (tab. 3).

Comparing the data acquired in both seasons we find dependence of the trophic structure on soil moisture. In moisture-deficient soils predators dominate in weight and the percentage of sapro- and phytophages is not high. The increase in moisture content up to a certain level leads to a considerable growth in weight and percentage of the phytophages or of mixophages also

35 mostly inclined to phytophagy. Lastly, an excess of moisture renders a dramatic effect on the abundance of phytophages and the role of both saprophages and predators is relatively increasing.

Our censuses and observations encourage to state that during the wet season the animal population aspect changes in every soil type similar to changing of vegetation aspects characteristic of the savanna as a whole (Cesar and Menaut, 1974; Meraut and Cesar, 1982), this may be explained by changes in the temperature and soli moisture content, structure of the vegeta­ tion cover and a high rate of growth and metamorphosis characteristic of tropical species. For instance bugs (genus Geotomus, fam. Cydnidae) in the beginning of our samplings were represented by larvae of various early instars. A week later there were mostly larvae of the latest instars and adults. One more week later their mass flight was observed and testing samplings in these soils revealed solely mature individuals whose numbers was a lower by an order. That is why the data obtained In October 1987 probably characterize only a part of the animal population Inhabiting soils in the wet season.

A preliminary analysis showed a considerable Increase In the numbers of systematic groups In every biotope. During our surveys the most numerous groups were: earthworms (fam. Eudrilidae)', woodlice; spiders (Lycosidae, Zodariidae, Araneidae, Thomisidae, Oxlpoidae, Dictinidae, Unyphiidae, Gnaphosidae, Uioboridae, Oonopidae); Diplopoda, fam. Spirostreptidae; Geophiiomorpha, fam. Medstocephaiidae; Uthobiomorpha, fam. Henicopidae, (genus Lamyctes)-, bugs, represented mostly by two families: Cydnidae (genus iIL 9 I Geotomus) and Lygaeidae-, ground beetles; Staphylinidae; Scarabaeidae tribe/ ) Sericini; larvae and Imagos of Tenebrionidae and Lepidoptera larvae. Practl- cally in all the soils termites were found whose number exceeded the one in the dry season several times. The composition of herpethobiontic groups of invertebrates changed in the wet season (tab. 5). Their abundance grew a few times. Most notably grew the number of phytophagous groups, particularly that of Gryllidae, Acrididae, Cydnidae. Almost in all the biotopes both crickets and ants prevailed. In the forest on ferralitic soils Cydnidae and Acrididae also dominated. The latter family was abundant also in the gramineous grassland on brown siallitic savanna soils.

Soil animal population of agricultural lands.

The composition of animal population complexes of cultivated fields is much more scanty than that of savanna (tab. 6). Due to concentration of phytophages the numbers of invertebrates under cotton and sorghum plantations is sufficiently high. On vertisols under rice the abundance is almost thrice as low as in gramineous grasslands or under a forest on the same soils. Irrigation leads to a degradation of physical properties of these soils creating unfavorable conditions for invertebrates' activity. In the fields where crops (sorghum and maize) are cultivated by traditional methods, where almost no agrotechnical measures are implemented and the tree layer is partly preserved, the invertebrate population is similar to the population of natural biotopes and is much more diverse than under state-possessed monocultivars. As to trophic peculiarities the invertebrate complexes of agrocenosis are divided into two groups. 1) Population of sorghum and maize fields (traditional agriculture). 2) Population of rice, cotton etc. fields (state- possessed monocultivars). In the first group during the dry season mixo- trophic groups dominate and in the wet season, the saprophages. In the second group both in the dry and wet season phytophages prevail (tab. 7).

37 The numbers of mao-ofauna grows 1.5 times during the wet season In comparison to the dry one on irrigated lands, while on the fields with traditional agriculture it grows almost threefold. ' ’ .. •J/-' •<’ '

Among the invertebrates studied all the mass phytophages may be described as pests of different crops. For most of soils, the main phytophages were crickets. Besides, them mass phytophagous groups were outlined for every crop. Thus, for the sorghum fields those were the beetles and larvae of ‘r° nebrionidae; the Pyrrhocoridae bugs and Dermaptera for cotton fields; ■totalpidae for sugar-cane fields; Dermaptera for soya fields. The pest v.omposition is quite diverse on maize crops; Diplopoda (fam. Paradoxosomatidae), Tenebrionidae, Lepidoptera larvae (tabs. 4, 5). According to our route visual observations big damage to crops Is caused by ust (especially to plants at the earty vegetative stages).

The animal population of the fields Is formed at the present mostly dot to the local fauna (tabs. 5, 6). For the greater part the fields are infested by phytophagous invertebrates preferring In the natural conditions either alluvial soils (Acrididae, Dermaptera) or sufficiently humid biotopes (Gryllidae), anc1 also invertebrates which inhabit in natural biotopes the soils similar to those of the fields. Several species damaging to crops, for example, Disdercus spp. (fam. Pyrrhocoridae) were imported into that region.

According to our observations the numbers of many pests are effectively controlled by fires, which prevent mass reproduction and rapl# growth of phytophages. Growth in area of relatively uniform fields creates favorable conditions for mass proliferation of several new pests (locusts, AJeirodid$, Noctuidae, Alticinae) able to pass the whole life history on the field.

38 In conclusion we would like to list the main traits of population of the soil layer of savanna and agricultural lands.

1. At least two different aspects are characteristic of the animal population of savannaMihose of the dry and the wet weasons. Thus either aspect is thereby characterized by its own abundance level and dominance structure.

2. The beginning of the dry season is followed by migration of several groups of invertebrates to more humid biotopes. Partially the invertebrates survive the unfavorable season in the stage of egg, pupa or partly in imaginal diapause.

3. Destruction of litter and the dry grass during fires diminishes drastically the food resources available for saprophages, thus leading to a restructuring of the whole trophic chain. The main consumers of organic matter then are the phytophages.

4. There is a strict dependence of phytophages abundance on soil moisture content: an increase in soil humidity up to a certain level results in growing of numbers and weight of the phytophages; a further increase in soil moisture is followed by a decrease in the abundance and weight of phytophages and an increase in those of saprophages.

5. By the composition and numbers of soil animal population in the dry and wet seasons one can conclude as to the soils rate of potential biological activity, and thus judge on their fertility. In particular our opinion on the

39 fertility of tropical ferralltic soils based on the results of our researches corre­ sponds to the conclusions of soil scientists, who recommended these soils for intensive agricultural development.

6. The formation of the fauna of the fields at the present is due for the most part to the groups from surrounding natural communities. The numbers of many pests is controlled now by fires.

7. Application of traditional ameliorative and agrotechnical measures on vertisols leads to a degradation of soil physical properties, a decrease in their biological activity, and consequently in their productivity.

REFERENCE

Athias F. Les Microarthropodes du sol. Analyse d'un ecosysteme tropical humide: la savane de Lamto (Cote d'Ivoire), V.Les organismes endoges Bull Liaison Chercheurs Lamto. 1974, Numbero Special 5. 55-89

Athias F., Josens G., Lavelie P. Traits generaux du peuplement endoge de la savane de Lamto (Cote d'Ivoire). Progress in Soil Zoology: V Int. cong. Soil Zoology, Prague, 1973, Praga, 1975, 389-397.

Athias F., Josens O., LaveWe P. Le peuplement animal des sols de la savane de Lamto. Analyse d'un ecosysteme tropical humide: la savane de Lamto (Cote d'Ivoire). V.Les organismes endoges. Bull. Liaison Chercheurs Lamto. 1974, Numero special 5.45-54.

Cesar J„ Manaut J.C. Le peuplement vegetal des savanes de Lamto Analyse d'un ecosysteme tropical

humide: la savane de Lamto (Cote d'Ivoire) Bull Uason Chercheurs Lamto. 1974, Numero Spedal 2, 1-161.

Duchaufour F. Precis de pedologie Ed.2 Parts: Masson, 1965, 461 pp.

Olrard C. Les peuplements de larves endogees de Coleopteres dans les savanes de Lamto. Bull. Liaison Chercheurs Lamto, 1973, 35-37

40 Goffinet G. Etude comparative des effectifs de quelques groupes arthropodiens du sol intercalique de quatre biotopes Katangais. Ann. Univ. Abidjan, serie E: Ecologie, 1973, 6, 2, 251-256.

Goffinet G. Ecologie edaphique des milieux naturei. du Haut- Shaba (Zaire). 1. Caracteristiques et sinecologie comparee des zoocenoses intercaliques. Rev. Ecol. Biol. Sol., 1975,12, 4, 601-722.

Goffinet G., Freson R. Recherches synecologiques sur la pedofaune de I'ecosysteme Foret claire (Miombo). Bull. Soc. Ecol., 1972, 3, 2,138-150.

Josens G. Recherches ecologiques dans ia savane de Lamto (Cote d'Ivoire): Donnees preliminaires sur le peuplement en Termites. La Terre et la Vie, 1971, 2, 55-72.

Lavelle P. Les vers de terre de la savane de Lamto (Cote d'Ivoire): peuplements, populations et fonctions dans 1'ecosysteme. Thesies, Univ. Paris VI, Paris, 1978, 301 p.

Lavelle P. The soil fauna of tropical savannas. I. The community structure: In.: Ecology of Tropical savannas /Ed. B .J. Huntley and B.H. Walker/Ecological studies, Springer-Veriag, Berlin - Heidelberg - New York, 1982, 42, 477-484.

Levieux J. Donnees ecologiques et biologiques sur le peuplement en fourmis tem'coles d'une savane preforestiere de Cote d'Ivoire. Thesies, Univ. Paris VI, Paris, 1971, 300 P.

Mennaut J.C., Cesar J. Structure and Dynamics of a West African Savanna. Ecology of Tropical savannas/Ed. B.J. Huntley and B.H. Walker/Ecological studies, Springer-Veriag, Berlin-Heidelberg- NewYork, 1982, 80-100.

Pokarzevsky. A.D. The abundance and biomass of animal population of the soils in the mountain savanna ecosystems on black tropical soil in Shewa Province (Ethiopia). 1986. Ecologia, 4, 82-84 (In Russian). flfcpzanov B.G., Rozanova I.M. Correlation of impressions of the soil catena in the East Africa along the 900 km. long profile from Kisumu (1. Victoria) to Mombasa (Indian Ocean) in Kenya. Problems of Soviet soil science. Soviet soil scientists for the XII ICSS. 1982. Moscow, 135-139. (In Russian).

Rozanov B.G., Cheliadnik P.T. The soils of Gambela region of Ethiopia. 1983. Vestnik MGU, ser. 17, Pochvovedenye, No 4, 9-14. (In Russian).

Sizov V.V. Soil cover of the Baro-Akobo interfluve (this issue).

41 Some agrochemical parameters of soils of the studied testing plots in thfc Baro-Akobo interfluve

Soil parameters Plot Phytocenoses Type Soil horizons. Humus pH Mobile Texture No or crops of sampling % V. P2O 5 K20 soil depth sm 1 Xerophytic F b° AoA, 0-1 7,1 7.35 29,2 110,5 light loam deciduous Ai 1-5 5.8 7,05 16,8 62,4 light loam forest Ai 5-15 3.2 5.5 11.9 18,6 clay loam A,B 15-40 2.6 5.0 12,1 11.8 day loam 2 Xerophytic Be AoA, 0-1 ■ 6.35 7.25 24.4 16.2 loamy sand deciduous Ai 1-5 5.3 7.5 29.7 27.0 loamy sand forest Ai 5-20 1.3 7.0 11.2 10.2 loamy sand A,B 20-40 0.6 7,25 8,9 10.2 loamy sand 3 Gramineous Be AoA, 0-1 3.1 8.75 44,6 40.7 light loam grassland A, 1-10 2.5 6.45 26,5 29.3 light loam A,B 10-20 1.7 5.05 12,8 23.6 medium loam

8 . 20-30 1.4 4.95 13,0 5.2 medium loam 4 "Xerophytic Vp AoA, 0-1 12,3 7.45 120,4 36,8 clay loam forest Ai 1-5 8.07 7,35 82,2 41.5 clay loam A, 5-20 3.0 8.6 18.7 16.1 light day A,B 20-40 2.5 6,0 9.7 14.7 light day 5 Gramineous Vp AoA, 0-1 9.0 5,85 78.5 37.1 day loam grassland Ai 1-5 7.4 5.5 43.6 26.5 medium loam A, 5-15 4.3 5,4 32.5 10.6 light day A,B 15-30 2.3 5.5 17.9 9.4 light day 7 Sorghum Be A, 0-1 3.9 7.0 62.1 20,6 loamy sand field A, 1-5 3.3 7.0 70.4 18.2 loamy sand A,B 5-20 2.6 6.6 53.4 9.8 loamy sand A,B 20-40 1.5 7.5 54.3 8.6 loamy epnd 8 Rice Vp AoA, 0-1 3.97 8.7 35.7 11.8 medium loam field A, 1-5 3,94 6.7 26,2 11.3 day loam A, 5-20 3.74 6.6 18.7 12,0 day loam A,B 20-30 2.23 6.8 11.2 6,8 light day

42 Table 2

Soil invertebrates numbers in different savanna communities ______(ex/sq.m; sampling dates)______Time Beainninq of dry season 27.11-29.12.1986 End of wet season 9.10-6.11.1987 Plot N° 1 2 3 4 5 1 2 3 4 5 Phytocenoses Xero­ Xero­ Gra­ Xero­ Gra­ Xero­ Xero­ Gra­ Xero­ Gra­ phytic phytic mine­ phytic mine­ phytic phytic mine­ phytic mine­ deci­ deci­ ous forest ous deci­ deci­ ous forest ous duous duous gras­ gras­ duous duous gras­ gras­ forest forest sland sland forest forest sland sland Soil types Fe° Be Be Vp Vp Fe° Be Be Vp Vp Total numbers * 84 162 107 227 227 838 304 156 178 168 (ex/sq.m) Total biomass’ 2172,7 3244,8 782,1 3855,4 2492,5 11772,6 6243,6 1720 1254 1672,4 (mg/sq.m) Nematoda: 4 4 12 Mermithidae Oliaochaeta: 3 4 11 38 4 4 8 8 Eudrilidae Crustacea: 3 5 8 12 16 8 Oniscidae Arachnida: 15 25 21 51 32 68 32 20 64 36 Aranei MvriaDoda: 11 3 24 16 4 4 24 Diplopoda Geophilomorpha 5 16 8 3 16 8 8 Lithobiomorpha 1 3 12 20 4 Insecta: Diplura: 3 3 16 Japygidae Blattoptera Isoptera** 16 24 11 40 280 400 160 Orthoptera: 2 5 4 Gryllidae Dermaptera 12 HemiDtera: Cydnidae 49 136 Lygaedae 3 3 11 12 Other Hemiptera 3 5 4 6 4 4 Coleotera: Carabidae 3 40 16 larvae Carabidae 9 27 8 8 48 16 © 12 imago Histeridae im. 4 4 4 Staphylinidae 1. 4 16 Staphylinidae im. 11 3 5 13 8 4 4 8

43 Table 2 (Continue)

Scarabaeidae 1. 8 67 11 3 35 4 104 12 4 Scarabaeidae im. 3 3 3 14 13 4 4 Anthicidae im. 2 8 1 37 Elateridae 1. 5 5 8 Tenebrionidae 1. 8 11 8 16 12 36 Tenebrionidae im. 3 3 5 4 4 2 Curculionidae 1. 3 16 Other Coleoptera 1. 3 5 8 4 Other Coleoptera im. 2 3 2 18 4 16 4 Diptera: Asilidae 3 5 3 4 Other Diptera 1. 4 12 Lepidoptera 1. 1 3 10 3 20 16 20 12 Other groups 3 6 12 8 8 12 4 8 4 Eggs of insects** 24 811 4 20 Average numbers (M) 5,24 "0,1 6,7 14,2 14,18 52,4 19 9,75 11,1 10,5 per sample Stan4ar1 deviation 0,58 1.2 0.6 1.08 O.M 4.2 2,00 0,78 0,76 1.6 (m) Standart deviation % 11 12 8.6 14 7 8 11 6 7 15; • (m%) * — not including termites

*’ — not included In total numbers Table 3

Ratios of trophic groups of soil macrofauna in different savanna phytocenoses

Time Beginning of dry season 27.11-29.12.108e End of wet season 9.10-8.11.1987

PlotNN 1 2 3 4 •6 1 2 3 4 5

Phytocenoses Xero­ Xero­ Ora* Xero­ Gra­ Xero­ Xero­ Gra­ Xero­ Gra­ phytic phytic mine- phytic mine­ phytic phytic mine­ phytic mine­ deci­ deci­ ous forest ous deci­ deci­ ous forest ous duous duous gras­ gras­ duous duous gras­ gras­ forest forest sland sland forest forest sland sland Soli types Fe8 Be ••Be Vp Vp Fe° Be Be Vp Vp Trophic groups (% of total biomass) Phytophages 20.8 38,0 21,1 74,1 58,5 72,8 23,0 70,2 21,2 11,5 Saprophages 8,1 8,0 9,1 22,4 11,5 16,9 16,7 47,7 31,6 Group of mixed 21,1 57,2 2 7,2 0,4 5 3,3 51,2 7.4 0,4 4,2 trophology: phyto­ phages and saprophages

Predators 47,0 6,8 42,7 16,4 14,0 12,6 8,8 5,7 30,7 50,9 Parasites 0,02 0,03 1,8 Total numbers* 84 162 107 227 227 838 304 158 180 188 Ind/sq.m Total biomass* 2172,7 3244,8 782,1 3855,4 2492,5 11772,8 8243,8 1720 1254,4 1872,4 mg/sq.m Total numbers 280 400 180 of termites** (Ind/sq.m) Total biomass 818 880 352 of termites** mg/sq.m

Note without termites; ** - values are considerably low (acquired only from digging data) Table 4

Composition and abundance cf harpathobionta in savanna phytocaooaea and agrocenoses at tha beginning of tha dry saaaon (Novambar-Oacambar 1986)

Plot No 1 2 3 A 8 ' 7 iO ■ J - » . Pfiythocenoses Xero­ Xero­ Grami­ Xaro- Grami­ Cot­ Sorg­ Socg- Ri­ Sugar- and agricultural phytic phytic neous Dhvtic neous ton hum hum ce cane . Z9 crops: forest forest grass­ forest ’ V * > * land land VV- Soil types Fe° Be Be Vp Vp Be Be Al Vp------Al Al f r z ? Invertebrates groups: •V- Aranei *********** ** *** ** : ♦ Oiplopoda !. (Paradoxo- . I • • A •• somatidae) I ’* .'-1 Lithobio-morpha Orthoptera: Grillidae I ’ GrylSotaipidae Dermaptera , ' ; Hemiptera: * " * ■£ • 3 Cydnidae Pyrrhoridae ■ V V Coleoptera: Carabidae im. Staphylinidae im. i Tenebrionidae | im. it « ■ Lepidoptera larvae Formicidae im. - t i l ____ 2 L___ — ---- - *> Note: ;>• +++ — superdominating group (over 50 ex7100 traps per day) : V . *+ — dominating group (2 0 -5 0 ex./100 traps per day) + — subdominating group (10-20 ex/100 traps per day) .S'

46 Table 5

Composition and abundance of herpethobionts in savanna phytocenoses and agrocenoses at the end of the wet season (October, 1987)

Plot No 1 2 3 4 5 6 7 8 12 13

Phythocenoses and Xero- Xero- Grami­ Xero- Grami­ Cot­ Sorg­ Rice Sugar­ Soya agricultural crops: phytic phytic neous phytic neous ton hum cane forest forest grass­ forest grass­ land land

Soil types Fe° Be Be VP . Vp Be Be Vp Vp Vp Invertebrates groups:

Aranei ++ ++ + + ++ ++ ++ ++ ++ ++

Oniscidae +

Blattoptera +++

Orthoptera: Gryllidae +++ ++ ++ ++ ++•*■ +++ ++ +++ +++ +++

Acrididae ++ ++ Dermaptera ++ ++ ++ Hemiptera: Cydnidae +++ Pyrrhocoridae + + Coleoptera: + + ++ + + + + + + + + Carabidae im. Tenebrionidae im. + + + +

Formicidae +++ +++ ++♦ + ++ ++ +♦ ++ ++ + +

Note:

+++ — superdominating group (over 100 ex7100 traps per day) ++ _ dominating group (50 - 100 ex./100 traps per day)

+ — subdominating group (10-50 ex./100 traps per day)

47 Table 6 Abundance of soil invertebrates in agrocenoses according to sampling dates ______Time Beginning of dry season End of the wet season (Dec. 1986) (OcL-Nov. 1987) Plot No 6 7 8 6 7 8 Agricultural crops: Cotton Sornhum R,ce Cotton Sorghum Rice Soil types Be Be vp Be Be Vp Total numbers* 192 115 69 216 332 120 Total biomass (mg/sq. m) 3478.4 1625,1 706,4 4504.4 3367.6 1411,6 Invertebrate groups: Nematoda: Mermithidae 3 20 Oiygochaeta: Eudrilidae 5 8 56 Crustacea: Oniscidae 3 8 Arachnidae: Aranei 32 29 13 32 52 16 Myriapoda Diplopoda 3 20 Geophilomorpha 8 8 8 Lithobiomorpha 3 4 16 Insecta: Oiplura: Japigidae 12 Thysanura: Lepismatidae 12 Isoptera" 220 245 Othoptera: Gryllidae 3 Hemiptera Cydnidae 56 Lygaeidae 8 5 8 4 Pyrrtiocoridae 72 92 Other Hemiptera 6 8 4 Coleoptera: Carabidae larvae 3 Carabidae imago 8 11 4 8 12 Staphylinidae im. 16 10 5 4 44 4 Staphylinidae larvae 16 Scarabaeidae im. 8 Elatendae larvae 11 3 4 6 Anthiddae im. 8 3 5 20 8 Tenebrionidae larvae 8 19 20 Tenebrionidae im. 3 Curculionidae larvae 3 Curculionidae im. 3 Other Coleoptera (im.. pupae) 24 12 24 Diptera larvae 8 Other groups 12 12 20 Eggs of insects unidentified" 5 Average numbers (M) per sample 12 7.2 4.3 13,5 20.8 7,5 Standard deviation (M) 1,68 • 0.79 0,26 1,62 1,66 1.4 Standard deviation % (M%) 14 11 6 12 8 19.

Note: * — not including termites: ** — not included in total numbers.

40 Table 7

Ratios of trophic groups of soil macrofauna under different agricultural crops

Time Beginfng of dry season 01.12 End of the wet season -18.12.1986 19.10.1987

Plot No 6 7 8 6 7 8

Agricultural crops: Cotton Sorghum Rice Cotton Sorghum Rice

Soil type Be Be Vp Be Be Vp

Trophic groups (% of total biomass): ■

Phytophages 80,5 13,6 59 88,7 19,7 96,9

Saprophages 13,4 18,8 9,0 66#> 0,8

Group of mixed trophology type: 7.7 62,2 2,6 0,1 5,9 phytophages and saprophages

Predators 11.8 10,4 21,6 2,2 6,8 2,3

Parasites 0,2 0,8

Total biomass* (mg/sq.m) 3478,4 1825,1 706,4 4504,4 3387,6 1411,6

Total numbers* (ind. sq. m) 192 115 69 216 332 120

Total biomass of termites** (mg/sq.m) 484 539

Total numbers of termites** (ind./sq.m) 220 245

Note:

* — without termites;

** — values are considerably lower (acquired only from sampling data)

49 SOIL FAUNA OF THE DRY SAVANNA AND AGROCENOSES OF THE ABYSSINIAN UPLAND OF ETHIOPIA

B.R.Striganova, L.B*Rybalov

The comparative studies of the soil animal population (macrofauna) in the dry savanna and agrocenoses were carried out on the Abyssinian Upland in Ethiopia. The total population density and zoomass of the soil macrofauna in the Abyssinian mountain savanna was found to be 5-6 times lower in comparison with more humid savannas of West Africa. In contrast to the West Africa the relative weight of saprophaga Is reduced in the Abysslnicyi savanna up to 69% of a total zoomass. The agricultural development results in essential modification of the taxonomic structure of the soil fauna, and to considerable impoverishment of the animal population of soil. First of all an abundance of useful forms participating immediately In soil formation processes is reduced.

Introduction

Savanna ecosystems occupy almost a half the territory of Ethiopia. A considerable part of savanna landscapes has anthropogenic origin. The. anthropogenic savanna developed within centuries as a resu^ of an extensive agriculture, and entertainment In agricultural use of wood territories. Initially the territory of the Abyssinian Upland was occupied by dry subtropical coniferous forests, where Podacarpus and treetype Juniperus were main edificators. In the beginning of the XIX century in Ethiopia the fissile activities on forest restoration begun. But the native slowly growing

50 confferous forests were replaced by a fast rising eucalyptus. The prolongation of a restoration cycle of eucalyptus under natural conditions of Ethiopia is about 10 years. The removing of native forests was promoted also by the conventional live stock with the extensive type of grazing.

On •deforested territories perennially used as pastures, savanna habitats have been formed which are characterized by the predomination of a bush vegetation including numerous ruderal and polytopic plant species.

At present the Ethiopian savanna is completely used for grazing, the high pasture press becoming the stressing factor. The agriculture in this country Is conducted till now by conventional ways: with usage of shallow plowing by primitive plows, absence of fertilizers etc. Besides there has been cultured a rather restricted set of cultures - teff (Eragrostis abissinica), wheat, leguminoses, durra (Sorghum ), maize play the predominant role in the recent agriculture.

This paper presents the comparative analysis of the structure and btodlverslty of the soil animal population in the anthropogenic savanna and agrocenoses on the Abyssinian Upland.

The diversity characteristics of soil communities indicate a level of the soil biological activity and stability of soil biodynamic processes under conditions of the anthropogenic ^effects. Among the actual pests rendering the economic injury to agricultural cultures, soil invertebrates play the considerable role, they damage roots and other underground plant parts. The representatives of different insect orders and some species of myriapods

51 (Diplopoda) include in pest communities damaging peanut, soybeanr sorghum, and other widespread cultures. Root aphids play a leading role among soil pests, because they decrease the plant stability to a drought. The roots damaged by aphids represent a path for Invasions of pathogenic fungi, they are attacked by termites, which are especially active during dry seasons. Some termite species destructed up to 50% of primary production in agrocenoses. Species of ants, beetle larvae of Alleculidae Tenebrionidae, Buprestidae, Curculionidae, Chrysomelidae (Galerudnae) also belong to active pests. The representatives of orthopterans, soft scales and armored scales concern also to a number of the pests. In more wet soils an essential role as the pests gain Diplopoda (Wlghtman, 1991; Slthawanthran, 1991; Jayaraj et a l., 1991). • I f I ‘SB*I * •

In tropical regions a little attention has been given to a comparative analysis of the structure of the soli animal population, both in natural ecosystems, and arable lands, what allows to reveal a potential of pests and f ** . •: „ \ their possible natural enemies among the autochthonous fauna.

Research region, material and methods

The material was collected In Ambo region (province western Shoa) at the altitude 2100 m over sea level under 37.5° E and 9° N. This region includs into the dry savanna zone. The climate is characterized by presence of two seasons, with the annual ^um of precipitations of 1200-1300 mm. The maximum of precipitations Is recorded In a June-September period. The number of days with precipitations more than 1 mm / day - 138. Mean air

52 temperature means 16.5°C, with an absolute maximum 34.4° (June) and minimum 0°C (December).

The soil cover is represented by black tropical soils (vertsoil), typ/cal of dry regions of the Abyssinian Upland. Local names of these soils - "bedob" (Sudan) and vley (Kenya). The black soils are developed on flat ancient terraces (Ivanov et ah, 1985). They have a deep, poorly differentiated profile up to 80-100 c m , with a high content of the of clay fraction. In comparison with laterite red soils occupying more elevated areas, the black tropical soils are characterized by a rather low content of ferric hydroxide and very high content of manganese, that stipulates their dark colouration. In a structure of humus compounds dominate humate forms. The soils are characterized by a poor drainage. Some quantitative characteristics of these soils are shown in Tab. 1.

Table 1 . Chemical characteristics of the black tropical soil in the Ethiopian savanna.

Plots PH Hydrolytic Ca++ Mg++ C organic acidity (KCI) mg-equv./100 g % of soil Savanna 5.81 0.66 37.3 10.5 4.58 Wheat field 6.61 0.44 56.2 8.5 5.61 Bean field 6.58 0.66 51.9 8.9 1.28

The soil acidity (pH) was measured using the potentiometric technique, hydrolytic acidity, the contents of Ca++ and Mg++ - by complexometric technique (Kaurichev et al., 1986), organic carbon - by the Tjurin technique n the modification with the spectrophotometric termination (Orlov et al., 1967).

53 The natural plant cover is represented by a typical community of dry anthropogenic savanna, which formed on place of a disturbed forest. The plant cover represents the mosaic of a scrub cover composed by Eudea dtvinorum, Carissa edu/us and young eucalyptus trees and grass spots, where cereals predominate. Separate Individuals of treetype Euphorbia abyssinica , acacias (Acada abyssinica, Acacia spirocarpa, Acada pennata) and podocarpus (A gradlior) occur in the savanna habitats. Cereals Pennisetum villosum, Eragrostis panidformis, Aristida adoensis, Setaria incrossata, Themeda triandra, and also Eleusine floccifole, Hypoxis angustifblia, Kniphofia pumila, Rhamphicarpa heuglini predominate in the grass cover.

The quantitative studies of the soil macrofauna were carried out on the territory of the Agncultural Experimental Station Ambo. The savanna territory adjoining to the station area was used as the control. Experimental fields of wheat and bean fodder grassses were considered as the typical examples of Ethiopian agrocenoses. On the Station the agriculture is realized without pesticide processings, what permits to estimate changes of ’ / IF S ' the soil animal population determined by the soil plowing. The quantitative Investigations of soli macrofauna was conducted by the standard method of the extraction of soil cores 25 x 25 cm (Ghilarov, 1975) with processing by hand-sorting of separate soil horizons. In the field soil two horizons in the

soil profile were differentiated - arable horizon (0-10cm) and underlying layer

(10-20cm).

In the savanna a layer of the grass floor was developed on the soil

surface, which Investigated as Ao. 8 standard soil cores by the size 25x25 cm were sampled and processed in each habitat. The soil-zoological studies

54 were conducted in September - October 1992 (the beginning of the humid season).

Simultaneously the measurements of a soil zoomass were carried out using the individual weighting of separate animals before fixation. The indices of diversity and eveness were determined for local communities of soil invertebrates.

Shannon's diversity index: H’ = p. In pi (pi = n/N) n - number of individuals of one species, N - total number of individuals.

Pielou eveness index: E = H’ / log2S

S - number of species in the site (Wittaker, 1980)

Results

Both the taxonomic composition, population number and zoomass of the soil macrofauna in the experimental sites are shown in Tab.2. The total number of invertebrates in the savanna meaned 134 Ind./m2, in agrocenoses it does not exceed 64 Ind./m 2 ; the biomass in the savanna averaged 6.02 g/ m2 and in the agrocenoses it was six times lower. The abundance of soil animals in the savanna essentially varies on seasons. During a dry season it is sharply reduced in numbers and zoomass (Pokarjevsky, 1988).

The taxonomic richness of animal communities varied in separate sites. Representatives of 15 groups were recorded in the savanna, 12 groups - in the bean field, and only 9 - In the wheat field. Plantations of leguminoses occupy the Intermediate position between the control savanna

55 habitats and cereal agrocenoses which are characterized by the poor soil animal population in al natural zones. The bulk of numbers and zoomass of soil invertebrates in the savanna was composed by earthworms Eudrilidae forming 30,4% of the total population number and 36,9% of the zoomass. Diplopods play also the significant role in the savanna communities. Their biomass meaned 2 g/m2 (31.3%). These groups are absent in the agrocenoses, what determined the qualitative differences of animal communities.

Beside with Eudrilidae and Diplopoda such groups as Trombidiidae, Geophylomorpha, Japygidae, Cydnidae, Asilidae and Lepidoptera larvae were absent in the agrocenoses. But representatives of Reduviidae, larvae and imagines of Anthiddae, Tenebrionidae, Cucujidae, Elateridae and larvae of Neuroptera were recorded there. These groups were absent in the savanna. Mollusca, spiders, orthopterans, mole crickets and staphylinids were found in all plots investigated. The bulk of the soil animal population in the savanna is represented by litter and soil saprovores (earthworms and myriapods). They are absent in the agrocenoses, but there increased the insect diversity.

Soil invertebrates aggregated in the layer 0-10 cm. - 52% of animals were recorded there in the savanna and 97 -100% - in agrocenoses. 39% of the total animal in the savanna was found in the layer Ao. Deeper soil layers were poorly populated - only 9% of animals were found on the depth 10-20 cm. The same horizons in the agrocenoses were non-populated. It was determined by a poor drynage of soil with a high content of a clay fraction.

Patterns of the domination structure of animal communities in the savanna and agrocenoses are shown In the Tab.3. Three groups

56 predominated by the population densities In bean fields - StaphyHnRJae, Aranea and Carabidae] the remaining 9 groups were represented by separate individuals^ In the wheat fieid 5 from 9 detected'groups formed- . 84,5% from the total number of Invertebrates. The group of dominants In ' v the savanna composed 77,9% of the total number, from w hlch 30,9% averaged ollgochaets and 27,9% - spiders. . ” "•

Table 3 The domination structure of local communltfe*

Groups Savanna /"• ‘ Wheat field I ' / Bean fieW V ' % of total numbers . . • /«

Oligochaeta 30,9 ; ) -»-v . Aranea 27.9 i 56.3 Staphylinidae 8,8 . v ' r 6,3 « . e .•

Anthicidae 9 ,3 " . ; * ,•* V ' '<• . • *•

Carabidae : :«.-3 . 6 , 3 . - ' Gryllidae • Geophilomorpha 10.3 - ■ . ’ ‘ - • '• s" Total: • 77,9 . - m : v ; 71,9

The Tab.3 demonstrates, that spiders in the wheat Add/ stepJSytinids ^ in the bean field and ollgochaets fn the sayanha form ii»e population density of the macrofauna. At the same time spider* showed^ almost same abundance levels In both the savanna and bean fieW. pie bulk. of a biomass in a wheat field.was formed by spiders^d,.nv>le crldcet$/and;' In the bean field the tenebrtonld tarvae and woodtlce added td. the dominant

57 group. Thu* the spider* are tht most widespread group of the macrofauna ~ in all plot* Investigated. HI m 1 v Indices of dlvrslty and eveness of the local communities were gMctfated (Tab. 4). The maximum value of the Information diversity Index • rtiarecorded In the savanna. In the serliw: savanna - bean field - wheat ' field thb diversity Index value tends to decrease. Both the taxonomic richness and diversity were In the wheat field significantly lower, that those in two other plots. • t

> *• Table 4 . Taxonomic richneee end diversity of the soil animal communities

Plots Species richness Shannon diversity Pieiou eveness index index ■ L ■ Savanna 15 2.01 0.50 Wheatfteid 9 1.48 0.49 Bean field 11 1.71 0.47

/ The soil of the wheat field Is characterized by a low content of the ; organic carbon (See Tab. i j . So, the deficiency of organic matter and nitrogen Jn. soil results. In the low abundance and diversity of the soil fauna. presents patterns of the trophic structure of local animal eonynunltfes In Ambo habitats. 1 ^ , • .i * " ’ « »■

58 Table 5 . Trophic structure of soil animal communities

Plots - % of total numbers ; % of total zoomass Phytophaga Predators Saprophaga Phyto- others saprophaga

.Savanna 4,3:12,6 52,2:17,8 40,6:69,3 1.50,2 1 Wheat 12,5:34,2 81,3:64.1 0:0 6,3:1,6 0:0 field Bear*field 12,5:32,1 78,1:43,0 6,3/1,8 3,1:13,1 0:0

Predators form the most numerous trophic group in all sites. Their relative abundance averaged 52% - in the savanna and 81% in the wheat , field. Saprophaga are relatively numerous in the savanna only, they find there a sufficient supply of available plant remains for feeding. Earthworms Eudrilidae are absent In arable lands because of their sharp response to disturbances of a soli profile.

Discussion and conclusion

In the tropical savanna Lamto of Ivory Coast the climatic conditions are more humid. The mean population density of the macrofauna reached there 1160 Ind./m2. Juvenile stages of Pauropoda, Diplura and Eudrilidae predominated In animal communitues. They averaged about 20% of the total number and 96% of the zoomass (Athias et al. 1975a). Thus, the climatic humidity renders an essential effect on the taxonomic and trophic structure of the soil animal population. Saprophaga appears to be the rather sensitive group to different kinds of anthropogenic activities.

59 A burniryj out of the natural vegetation In the savanna Lamto resulted in almost twofold reduction of the abundance of saprophaga and sapro- phytophaga (Athias et ah, 1975b). At the same time an increase of abundance of termites and ants was observed.

In the dry Ethiopian savanna In areas with the non-dlsturbed plant cover the total numbers and biomass of the macrofauna was 5-6 times as low as In the savanna Lamto. The percent of saprophaga in local communities did not exceed 69% (on a biomass). The agricultural development of savanna lands In Ethiopia results lr the essential modification of a taxonomic structure of the soli animal population. Coefficients of biocenotlc similarity (Walnsteln, 1967) between animal communities of the savanna and arable soils averaged 29.5% (savanna / wheat field) and 20.2% (savanna / bean field). The biocenotlc similarity between both types of agrocenoses does not exceed 30%, what suggests about the considerable influencing of culture plants on the formation of so# fauna. Results obtained demonstrate, that the agricultural practice In the dry savanna leads to the considerable reduction of the soil animal population of a separate cenose. The role of useful soil-forming groups and primary decomposers of plant remains is reduced In arable soils first of all. But these negative changes develope by different ways under different plant cultures where are developed specific communities of pedoblonts. The agricultural plantations in Ambo region are surrounded by savanna plots, what permit migration exchanges of soil Invertebrates and survival of local populations In situations, when soil conditions In arable lands drastically change and become unfavorable. As a whole the diversity of soil fauna of the agro­ landscapes is higher, than that in fhe savanna.

60 Table 2 . Composition and abundance of soil animal communities (macrofauna)

Experimental plots Anthropogenic' Agrocenoses Groups and species savanna Wheat field Bean field 1* II* f II I II Oligochaeta 42 2387 (Megascolicide + Eudrilidae) • . -.i Isopoda 2 11 2 ; 114 Aranea 38 619 36 588,2 16 273 Acari (Trombidiidae) 2 2 r .» f. . Diplopoda 6 2024 Geophilomorpha 14 434 Japygidae (Japyx sp.) 4 45 Orthoptera (Tetrigidae) 2 11 2 32 Orthoptera (Grillidae) 4 318 2 268 Hemiptera (Cydnidae) ( i ) 2 14 Hemiptera (Reduviidae) ( l ) 2 25 Hemiptera others ( i ) \2 It 2 11 Coleoptera. Carabidae ( i ) 4 49 4 39,4 Staphylinidae ( i ) 12 50 4 20 81 Anthicidae ( i ) 6 4,8 2 1,6 Cucuidae ( i ) 2 2,6 Tenebrionidae ( i ) 2 128 Elateridae ( I ) ; -v 2 2,6 Coleoptera others (I) 2 r r Coleoptera others ( i ) 2 2 2 14 2 2 Diptera: * niul Asilidae (I) 2 4 Diptera others ( I ) 6 65 Neuroptera ( I ) 2 2 Lepidoptera ( I ) 2 384 Total per one sample 8,5 378,3 4 64,7 4 61,1 Total perm2 136 6052 64 M035 64 977,6

*) I - population density (Ind./m2), II - biomass (mg Im2) of soil invertebrates

61 »

REFERENCES

Athias F„ Jonas G ., LavaH* P. Trails generaux du peuplement animal endoge de la savane da Lamto (Cole d'lvoire)//Progress in soli zoology. Prague, 1875a. P. 375.

Athiai F., Jonaa O., LavaHa P. Influence du feu de brousse annuel suf le peuplement endoge de la savane de Lamto (Cote d'ivoirey/Progress In soli zoology. Prague, 1975 b. P 389-

Ghllarov M.S. Quantitative in ^estlgation of larga-slzed soil invertebrates (mesofauna) II "Methods of soH- zoological investigations' Moscow 'NauKa' 1975. P. 12. (Russ. Res.Engl.)

ja y a raj S., Rangan^an R., RaMndra R.J., Chandramhow N. Studies on the ecology of certain soil-bom Insect pests in Tamil Nadu State. India// ’Advances In manegment and conservation of son fauna*. New Dehli. Oxford and IBH PuN . 1991 P. 183.

Ivanov V.V., L tm n u O., Rozanov B.O., Sokolova T A . About the composition of soils of Ethiopian Upland II So« Science (Russia), 1985. No 3. P. 29-35.

Kaurichev 1.8. FEd.l Practicum on the soil science //Moscow, ‘AgropromizdaT 1986. 335 pp (Russ ).

Orlov O.8., Grundal N.M. Spectrophotometrlc analysis of humus content // Opnos AC., rpynnenb H.MV/ SOM Science (Russia). 1967 No 1. P. 112.

Pofcaifevaky A.O. Population numbers and biomass of the soil animal population of the mountain savanna ecosystems on biack tropical soils in the province Shoa (Ethiopia) // Ecologia (Russ.) 1986. No 4. P 82.

SMhawaitfftran 3. Studies on soil pests associated with ground-nuts in Zambia H ’Advances in manegment and conservation of soil f8una" New Dehli, Oxford and IBH Putt., 1991 P. 177.

Weinstein & A . About some methods of assessment of biocenoses similarity // Zool. Zhumal, 1967. V. 48 No. 7. P. 981.

VVIghtman J.A . SoH insect problems in African ground-nut crops // ’Advances in manegment and conservation of soil fauna* New Dehli. Oxford and IBH Publ.. 1991 .P. 171

Wlttaker R. Community and ecosystems. II Moscow, ‘ Progress’ 1980. 326 pp.

62

% VISCERAL LEISHMANIASIS IN ETHIOPIA AND ITS POSSIBLE NOSOAREA CHANGES.

[Kudoyarova I.Ya.l A.A. Luschekina and V.M. Neronov

Visceral leishmaniasis (VL) is a transmissible disease of man with characteristic natural focality in Its occurrence. It is a disease endemic over a wide area of the globe, affecting 400,000 new cases every year (WHO, 1990). ft is caused by Leishmania donovani, L. infantum and L. chagasi (Protozoa, Trypanosomatidae). The vectors of leishmaniasis are several ' species of sandflies (Insecta, Ph/ebotominae)) a number of rodent and carnivore species (Rodentia, Carnivora) serve as reservoir hosts. North and East Africa are parts of the world where VL is an endemic disease. Its prevalence in some counties of West, Central and Southeast Africa is sporadic (WHO/TDR/LEISHSWG, 1981,3). Epidemic outbreaks of VL were recorded in the Sudan and Kenya, where there were hundreds and thousands of patients (Ashford and Smith, 1985; WHO/TDR/LEISHSWG, 1981,3; Southgate and Minter, 1967). In the absence of treatment, the mortality rate of VL in Africa has been reported to reach nearly 95% (Habte- v -Gabr, 1982).

According to the prognostic maps made by S. M. Malhazova and V. M. Neronov (1983), the potential nosoarea of VL in Africa is considerably larger than It is currently known. There are vast areas where this infection is either absent, In spite of favorable natural conditions for the maintenance of the cycle of transmission, or it has not yet been recognized by local public health services. Active agricultural development usually results in large

63 scale migration of human populations leading to contact of large lum bers of non-immune individuals with the natural fod of VL. It can also result in the introduction of this infection into region that were free from VL Therefore, when plans for large scale agricultural development and resettlement schemes are thrown away, it necessary to consider prior Investigation of the areas as well as programmes for continued surveillance for VL. A review of available literature, as well as an appraisal of major characteristics of the epidemiology and epizootology of VL in Ethiopia, are given below.

VL in Ethiopia was recognized for the first time in 1914 by V. de Marzo in the region of Eritrea (Marzo, 1914). For the period 1939 to 1943 G. Ferro-Luzzi (1943) recorded another 9 cases. Although the localities of the infection were not exactly established, the author suggested that all the cases may have been from the lowland plains of the northwest of the country. For 30 years thereafter, there was no information about VL in man in Eritrea until the end of the 70s and the beginning of the 80s, when Ayele (1982) recognized and 8 parasitologically confirmed cases of VL In the environs of Algena and Nakfa towns, in the northeast lowlands of Eritrea. Between 1981 and 1983, 16 cases of VL were found among military men in the north and north-west of Eritrea (Ayele and All, 1983). All the patients were from the mountainous regions, where VL was not recorded and perhaps were infected while stationed in the lowlands. On the whole the data show the existence of active natural foci of VL near the towns of Algena, Nakfa, Afabet and Tesenei.

The reports of VL cases in the seventeenth were based on patients originating from the administrative region of Gonder on areas situated between the Metema and Humera in the Atbara and Tekeze rivers basins,

64 NW Ethiopia. People of highland origin were usually found affected, acquiring the Infection while working as labourers in the large-scale agricultural farms of Metema-Humera and Setit-Humera. The first 11 parasitologically confirmed cases of VL were reported in 1970 (Tekle et al., 1970). The increase in the morbidity rate during the succeeding years was explained by the increasing migration of non-immune population. As a result, Ayele (1982) suggested, that at the beginning of the 70s there may have been an epidemic outbreak of VL in that region. The total number of VL cases among hospitalized patients in different hospitals of Metema Humera region during the period 1970-1981 exceeded 100 (Jembere, 1982; Fuller et all., 1976a; Maru, 1979; Mengesha and Abuhay, 1978; Tekle et al., 1970). This number probably did not reflect the real number of VL cases, as only negligible proportion of patients reported to the health centers. The disease was consistently present in the region during all periods of the then active agricultural activity. The existence of natural foci of VL in this region was evident as revealed by other evidences too. For example, the percent positive skin tests (among of 1057 examined) was 45,6% for farmers and seasonal workers and only 8,3% among those in other professions. A direct correlation between the percentage of positive skin tests and age was observed i.e ., 23% among children of 11-15 and 82% among people aged 46-50 years. A similar correlation with the duration of stay in the region was also observed that is 3 months - 22% positive skin tests; 6 months - 30% and 8 years - more than 74% (Fuller et al., 1976b). In an entomological investigation of 1973/74, in the Shelala region of the Setit Humera plain, 20 000 sandflies were captured and identified as belonging to 6 species of Phlebotomus and 6 species of Sergentomyia (Gemetchu et al., 1975; 1977). P. orientalis was numerous during the dry season from November to June; with a peak in months of May and June. As ecological conditions of this region are similar to the Palolch territory In Sudan, where P. orientalis is the main vector of VL, It Is possible that the same species Is responsible for the transmission of the disease In NW Ethiopia too. Seven grass rats (Arvicanthls nlloticus) out of 117 captured In the Metema-Humera region, were naturally Infected by lelshmanla parasites (Halle and Lemma, 1977). However the species Isolated from the visceral organs of A. nlloticus, differed on the basis ov their biochemical and other characteristics, from Iso­ lates of VL patients In the same region (Chance et al., 1978). Importation of VL from the Northwestern plains to the nearby highlands by seasonal labourers that return to their homes In the highlands Is highly llkly to occur, For example, In the hospitals of Asmara, Axum, Gonder and Bahr Dar VL li often diagnosed In patients coming from the highland regions However, ai anamnesis usually shows, all the positive case* had at sometime worked in the Metema-Humera region where the Infection occurs. Between 1972 and 1979 six local cases of VL were reported from the highlands near Gonder and Belesa districts, situated south, southeast, and. east from Gonder (Ash­ ford et al., 1973; Maru, 1979). A few of the 6 patients probably never left their native settlements and didn't visit the regions endemic for VL.

Examination of sandflies and possible mammalian reservoir hosts (insectivores, rodents and carnivores) In Belesa district did not reveal infections by Lelshmanla parasites (Ashford et al., 1973). However the abundance of A. nlloticus - a potential reservoir of VL, the large number of P. drientalls and its anthropophlly creates favorable conditions for the appearance and possible endemldty of VL in these highland region*. ,A similar condition exists In the northeast of the country, In the middle and lower Awash river valley, with the ongoing agricultural development In the region, people from the highlands migrated and with the presence of VL foci,

88 the abundance of vectors and the existence of reservoirs hosts, all preconditions for a wider distribution of VL with potential for the appearance « of new foci that may result in epidemic outbreaks exists. Around the begin­ ning of 1970s based on clinical signs, (without parasitological confirmation) sever J cases of VL were reported from the red cross hospital of Gewani town (Fuller et al., 1976a). Also, 2 other cases among Afars, living in Djrboutf, not far from the Ethiopian border and the lower Awash river valley j were reported (Courtois, 1971). Examination of 269 men, conducted in the •. ;; 4.t f ' ; ' middle of 1970s in the middle and lower Awash river valleys, didn't reveal any active case of VL (Fuller et al., 1976a). However, 146 (54, 3%-men of the examined), skin test positive. Entomological investigation in this region ' showed the existence of 6 species of Sergentomyia and 2 species of Phlebtomus including P. orientalis (Gemetchu and Fuller, 1976).

Anderson (1943) reported human infection of VL in the South of Ethiopia among military personnel. However, the precise origins of the 19 patients were not determined. Between 1980 and 1987, 9 parasitologically •confirmed cases of VL were found in the administrative region of Sidamo, 1 situated In the south of the country, (Ayele and AM, 1983, 1984; Lindtjorn, 1980, 1987). The cases were from around Moyale town (2 cases); one came from Dawa and two others from Genale river valleys. Four other cases cane from the area to the east and northeast of Lake Abaya. Since no epidemio­ logical and epizootological investigation have been conducted in these • regions, the natural history of the disease and the transmission seasons were unknown.

SeveraL epidemic outbreaks of VL among the military had also been described in the middle of 20th century, from the Omo river valley and from

67 around lake Turkana (Southwest Ethiopia): that Is 30 cases in 1926 (Ayele, 1982; Omran, 1961); 31 cases In 1942 (Coles et al., 1942); and 20 cases during the Second World War (Ayele, 1982; Omran, 1961). The most serious outbreak was In 1939 (136 cases) among Kenyan servicemen, stationed on the southern and south-western Ethiopian border. Ten cases of VL were also reported among natives of the lower Omo river valley of which three were confirmed parasitologically (Anderson, 1943).

Between 1974 and 1979 Fuller et al. (1974; 1979) conducted a large scale survey of VL among the population of the Omo, Akobo and Sagan river basins, and of the Chew-Bahir and Chamo lakes. Parasites were detected In only 4 young men out of 2787 examined. The positive cases were from the Konso area (south of Chamo lake) and Hammer area (north-east of Turkana lake). Skin test positiveness was 32%, on the average, In 1974 and 44,9% in 1979 with highest percentage of positiveness among the males aged 10 to 20 years. An inverse correlation between percentage of positive skin tests and altitude was observed, that is 61-89,5% among the people living at an altitude of 500 m and 6,4% at 1400 m altitude. According to a brief regional report on morbidity rate of VL, 26 patients with parasitologically confirmed diagnosis were recorded in the hospitals of the administrative region of Gamo-Gofa (Southern Ethiopia) for the period 1980-1981 (Undtjorn, 1982). Lindtjorn and Olafsson (1983) having studied the problem of VL in Gamo Gofa in the same period, reported about 31 parasitologically proven cases. Following two years of observation in 1981-83, 32 parasitologically con­ firmed cases of VL were defected in Gamo Gofa administrative region (Ayele and All, 1983). Almost all case's were from the highlands In the range of 1500-1700 m above sea level, with the majority of patients being inhabitants of Abaroba locality (1480 m). However, Interviews of the VL

66 patients about their places of residence and work revealed that they most probably acquired the Infection from the lowlands (600-700 m) in the Sagan and Weyto river valleys (Ayele and All, 1983; Lindtjorn and Olafsson, 1983). It Is difficult to determine the Incidence of the disease in the region based on the above reports since the data reported seem to be overlapping. Furthermore, as Ayele (1982) and Ayele and All (1983) expressed, all recorded cases of VL In South-west Ethiopia are Just the tip of an iceberg, as only a small fraction of the patients would be expected to report for medical help. There Is however no doubt about the existance of endemic foci of VL in the Segen and Woltu river valleys.

The transmission patterns of VL in the SW Ethiopia in particular the lower Omo regions Is not yet established. However, in the entomological surveys carried more than 10 years ago, 13 species of Sergentomyia and 6 species of Phlebotomus that Included four specimens of P. orientalls were found in the areas around Omo river (Gemetchu et al., 1976). Some limited studies on the reservoir hosts exist. However no leishmanJa were isolated from tissues of 25 Arvicanthis nlloticus and 1 Xerus rutilus captured from the plain in Omo valley (Houln et al., 1968).

During the months of February, March, November and October in 1987 zoological and entomological reconnaissance surveys were conducted by our team (A.A. Luschekina) in Illubabor administrative region between the Baro and Akobo rivers in SW Ethiopia, with the aim of identifying natural foci of VL in the area. In this survey, 144 small mammals were caught using 522 live traps and break-back traps, both In natural habitats (high-grass land on a flat non-drained plain with burned plots; high-grass land on elevated and non flooded plain along the Gilo River) and from locations altered by man

69 activities (crop and cotton plantations & settlements). About 80% of captured rodents were from stations altered by human activities (generally in settlements or near them) and belonged to one of the following spedes: Genetta tigrina (2 specimens); Crocidura flavescens (5 spedmens); Gra- phiurus murinus (12 specimens), Tatera valida (18 specim ens); 83 specimens of Mastomys sp. and 24 specimens of Arvicanthis dembeensis. Microscopic examination of impression smears from liver and spleen of these animals didn't reveal any Leishmania. 1

In February and at the beginning of March, 150 sticky nraps were placed in human settlements. No sandflies were caught. In October and at the beginning of November these sticky traps were placed in the same stations (inside buildings and soil crevices) and caught 9 sandflies of the genus Sergentomyia. That is 3 males of Sergentomyia (Grassomiyia) ghesquierei, 1 male and 2 females of Sergentomyia magna, l female of S. africana, 1 female of S. ingrami and 1 female of S. cincta. It must be noted that all sandflies were caught at the end of wet season. However the absence of P. orientalis was evident. Probably this and other species became more numerous during the later months. In this connection, it is extremely necessary to continue detailed investigation on the composition of sandflies and their seasonal abundance, and at the same time to determine the natural foci of VL on the territory between the Baro-Akobo rivers located in the southwester part of the vast lowland plains along the Sudan - Ethiopia border. Ashford and Smith (1985) believe this area to be a "macrofocus" of

We thank the collaborators of Martsinovski Institute of Medical Parasitology and Tropical Medicine (Moscow) D r. M.V. Strelkova for carrying out of smears microscopy and D r. M.M. Artemiev for identification of sandflies species.

70 VL. According to the regional division of nosoarea of VL in Africa (Malhazova and Neronov, 1983) this region belongs to the Sudan plain focal region. Considering the fact that the region lies adjacent to the hyperendemic foci of VL in Paloich district of Sudan (Ashford and Smith, 1985), the existence of VL foci is more than probable. It is practically impossible to develop and effectively carry out control measures in the region between Baro and Akobo rivers without knowledge about the structure of the focus as well as about its epizootic characteristics. Therefore, epizootological survey of this territory can be considered among the urgent tasks. Based on information available in the literature, the following general characteristics of natural foci of VL in Ethiopia can be given.

The regions, endemic for VL, are the lowland plains not higher than 1200 m above sea level, situated in the north, northwest, southwest, south, and perhaps also in the east of the country (Fig. 1). VL does not exist on the Ethiopian highlands. The isolated highland valley of Belesa (1800 m), where local cases of VL were found, is an exception (Ashford et al., 1973; Maru, 1979). Particular Figure 1. Distribution of VL in Ethiopia & Eritrea. attention must be paid to this report, Kay. 1 - areas over 1600 m above the tea level; 2 - lakes; a - Addls- -Ababa; 4 - localities wt>ere VL patients were recorded (literature data); 5 * VL endemic areas (a - the Metema Humera plain, b- the as it could be the first danger warning Omo river valley); 6 - survey area* In Baro and Akobo rtver basins (1987). In Ethiopia, about spreading of nosoarea of VL in to the high-mountain zone. The majority of VL case& are In the dry and secondary woodlands covered with Acacia seyal and Balanites

71 aegyptica and In scrubs along rivers. The dlmate of the plains is dry and hot with temperatures over 20°C all over the year and rainfall from 150 to 950 mm annually In different regions (Malhazova and Neronov, 1983; Ayele and All, 1984; Fuller et al., 1976a,b; Undtjorn and Olafsson, 1983; Schaller, 1973).

VL In Ethiopia is a disease of the rural regions. People get infected during agricultural activities (Ayele 1982; Ayele and All, 1983; Fuller at al., 1974, 1976; Gemetchu and Fuller 1976; Tekle et al., 1970). Epidemic outbreaks usually occurred among newcomers (Anderson, 1943; Ashford et al., 1973; Ayele, 1982; Ayele and All, 1983; Coles et al., 1942; Maru, 1979; Mengesha and Abuhay, 1978; Omran, 1961;, Tekle et al., 1970). However, at the beginning of 80s the highest annual Incidence rate of 5,2/1000 was recorded among the native population of Aba Roba focus in SW Ethiopia (Ayele and All, 1983; Lindtjom and Olafsson, 1983).

As a result of traditional division of labour and mode of life the men are infected more frequently than women. In 1981 - 1983 the number of males among the parasitologically confirmed patients of VL was 4 times more than that of females (Ayele and All 1983). The difference between the two sexes may also be explained by the fact that the men seek medical treatment more frequently than women. The high risk group Included mainly men of able-bodied age of 15-21 (Fuller et al., 1976). Also 56% of all patients of VL detected In the north, southwest and south of Ethiopia from 1981-1983, were men aged 15-29 years (Ayele and All, 1983).

The causative agent of VL in Ethiopia Is Leishmania donovani. Strains isolated from patients of VL from former Begemdlr province had the

72 following biochemical characteristics: serotype of B2 excretorlal factor, buoyant nuclear DNA density of 1.719, that of kinetoplast DNA - 1.704;- electrophoretical variants of Isoenzymes: malate-dehydrogehase-VII, glucose-phosphate-lsome-rase-I, glucose-6-phosphate-dehydfogenose-II, 6-phospho-gluconate dehydrogenase-UI. The strains Isolated from patl.eniis of VL, sandflies and some species of rodents in Kenya and Sudw, had the same biochemical characteristics (Chance et al., 1978).

Based on the epidemiological data, many researchers consider P. orientalis to be one of the vector of VL in Ethiopia (Gemetchu, 1982). This sandfly species was found in all regions of the country where VL was recorded: in Setit Humera (Gemetchu et al., 1975, 1977) and Belesa (Ashford, et al., 1973; Ashford, 1974), In the Awash river valley (Gemetchu and Fuller, 1976) and the middle and lower Omo river valley (Fuller et al.*,\ 1979; Gemetchu et al., 1976). However, the natural Infection rate In P. orientalis has not established (Ashford et al., 1973; Gemetchu et al., 1975; ' 1977; Le Blancq and Peters, 1986). The ecology of this species Is Inade­ quately studied in the country. It is known that in Setit Humera P. orientalis inhabit the soil crevices during the dry season (December-March). The peak of their abundance is in October and in May-June (Gemetchu et al., 1975; 1977). Near the town of Arbaya (Belesa district) situated at 1700-1800 m . altitude, the sandflies (P. orientalis) are numerous all the year, and Inhabit animal borrows and tree holes (Ashford et al., 1973; Ashford, 1 9 74). The y correlation between high percentage of positive skin test, existence of P.} orientalis and distribution of heavy clay soils, rich in hygroscoplc«nr»rneral montmorillonit, was observed, in the southeast of the country (Fuller et al., 1979). '

73 P. m artini - the vector of VL in Kenya was found in the east (around Dire-Dawa town) and northwest (Belesa district) where their abundance was considerably lower than that of P. orientalis (Ashford et al., 1973; Ashford, 1974; Parrot, 1936). In tne southwest of the country P. martini has recently been recorded from Konso area (Gebre-Michael et al., 1986) and also from Lower Omo (Hailu et al., unpublished). Distribution of this species as well as its role in transmission of VL need be determined. It is suggested that transmission of the parasite by sandflies takes place all over the year with a small peak In October, Ir the north and northwest of the country, and in March-May in the southwest (Ayele and All, 1983). The increase In transmission seems to depend on the "small rains", which is followed by an increase in sandfly abundance, resulting In an Increased human contact with places of infection, owing to the stepping up of agricultural activity during this period.

The reservoir of L donovani in Ethiopia is unknown. G. Conti In 1931 and later Batelll et al. In 1934 found 10 Infected dogs (Schaller, 1972; Geomedlcal Monograph #3) near the town of Asmara. However, as Ferro— i luzzi (1943) believed, these parasites were not the causative agents of VL In man. Natural leishmanial infection could not be demonstrated in dogs from Metema-Humera area or among small mammals (Insectivores, carnivores and rodents) in Belessa district (Ashford et al., 1973; Houin et al., 1968; Tekie et al., 1970). The lelshmania isolated from A. niloticus In Setlt- Humera and in the Omo river valley differed by biochemical characteristics from L. donovani (Haile and Lemma, 1977). However, it is assumed that, A. niloticus is the main reservoir of VL in Ethiopia by analogy of the foci of VL In Kenya and Sudan. But the possibility that other animal species may serve as a reservoir of this Infection cannot be excluded (Ayele, 1982; Ashford et

74 al., 1973; Ashford and Smith, 1985; Gemetchu, 1982; Haile and Lemma, 1977). There remains the need to identify the reservoir hosts of VL in different foci in Ethiopia.

The main clinical signs of VL in Ethiopia are the following: remittent fever with excessive sweating, anaemia, splenomegaly, hepatomegaly, leukopenia, thrombocytopenia, proteinuria, brittle hairs, swelling of the abdomen, hyperpigmentation of skin and nails. The incubation period ranges from 2 weeks to 2 years or 4-6 months on the average (Hebte-Gabr, 1982). Only one case of Post-Kala-azar cutaneous leishmaniasis was described (Demissie et al., 1983). African type of VL is a rapidly progressing disease, resulting in a lethal outcome when an appropriate treatment is lacking. The mortality rate in Ethiopia is high. For example, at the end of the 70s, in only one hospital of Gonder town 55,6% patients of VL had died (Mengesha and Abuhay, 1978).

An obligatory registration of VL does not exist in Ethiopia nor does a regular surveillance of the disease. A national research programme of VL was started in 1981-82 at the Institute of Pathobiology. In May 1981 a workshop was conducted at a national level. This programme is believed to give way to a control/surveillance programme through provision of vital data to help health planners and officials to consider VL as one of the national health problems of the country.

With the currently ongoing resettlements, human migration and agricultural development in the fertile lowlands, large numbers of highlanders would be confronted with VL infection. Outbreaks and epidemics of VL such as the ones recorded in Kenya and Sudan is a possible threat. It

75 is therefor necessary to determine the nosogeographical divisions and also to institute surveillance programmes in the most active natural foci of VL. in the country.

REFERENCES

Malhazova 8.M. and V.M. N«ronov. Regionalnaya geographta leishmaniozov, ch.1. ttogi nauki \ lehnlW, ser Meditslnskaya geographlya. Moskva 1983,12. 180 (in Russian)

Anderson T.F. Kala-azar in the East African Forces. E Afr Med J.. 1943. 20, 8 172-175.

Aahford R.W. Sandflies (Diptera Phtebotomidaa) from Ethiopia Taxonomic and Biological notes. J. Med. E n t. 1974. 11. 5. 805-818.

Ashford R.W., M.P. Hutchison and R.8. Bray Kala-azar In Ethiopia: Epidemiological studies In a highland valley Ethiop. Med J., 1973,11.4.259-284

Ashford R.W. and D.N. Smith. Leishmaniasis In Sudan Ethiopia and Kenya. Leishmaniasis. Elsevier Science Publishers. Amsterdam-New-York-Oxford, 1985, 1. 377-391.

Ayala T. Epidemiology of leishmaniasis. Leishmaniasis in Ethiopia: a handbook. Proc. of Workshop, 25- 27 May 1981. Inst Patho biol., Addis Ababa Univ., 1982, 29-39.

Ayala T. and A. Ali. Visceral leishmaniasis In Ethiopia, a result of two years' surveillance. Research Report, 1983, 1.1-8

Ayala T. and A. Ali. The distribution of visceral leishmaniasis in Ethiopia. Ant J. Trop. Med. Hyg.. 1984, 33. 548-442.

Chance M.L., L F . Schnur, S.C. Thomas and W. Peters. The biochemical and serological taxonomy of Leishmania from the Ethiopian zoogeographlcal region of Africa Ann Trop. Parasitol., 1978. 72,8, 533- 542

Coles A.E.C., P.C. Congrove and 0 . Robinson. A preliminary report of an outbreak of kala-azar in a battalion of East African Rifles Trans. Roy Soc Trop. Med Hyg., 1942, 35. 26-31.

Courtois D. Leishmaniase viscerale en Terrttoire francaise des Afars et des Issas Med. Trop.. 1971, 31. 5. 535-537

78 Demissie M., B. Mock, T. Yemane-Berhan and E. Habts-Gabr Post-kala-azar dermal leishmanoid case report and review. Ethiop. Med. J.. 1983. 21. 4. 266«267

Ferro-Luzzi G. Studi sul Kala-azarin Eritrea. Boll. Soc It Med. Ig Trop , Eritrea 1943 2. 3 5-8

Fuller G.K., G. De Sole and A. Lemma. Kala-azar in Ethiopia: survey and leishmanian skin test results in the middle and lower Awash river valley. Ethiop. Med. J., 1976a, 14, 2. 87-94

Fuller G.K., A. Lemma and T. Gemetchu. Kala-azar in Southwest Ethiopia. Trans Roy Soc. Trop Med Hyg., 1974, 68, 2, 166.

Fuller G.K., A. Lemma, T. Haile and C.L. Atwood. Kala-azar in Ethiopia: I. Leishmanian skin test in Setit- Humera. a kala-azar endemic area in Northwest Ethiopia. Ann. Trop. Med. Parasit.. 1976b. 70. 2, 147- 163.

Fuller G.K., A. Lemma, T. Haile and N. Gemedia. Kala-azar in Ethiopia: a survey of Southwest Ethiopia. The leishmanian skin test and epidemiological studies. Ann. Trop Med Parasit.. 1979, 73. 4. 417-431

Gebre-Michael T., Mutinga M.J., Ayele T., Gemetchu T., Hailu A. and Ali A. Visceral leishmaniasis in Ethiopia: A preliminary observation on the Phlebotomine sandfly fauna of the Segen valley, SW Ethiopia. IPB Research Report, 1986, #2, 7-13.

Gemetchu T. Leishmaniasis: vector and reservoir host. Leishmaniasis in Ethiopia: a handbook. Proc. of Workshop, 25-27 May 1981, Inst. Pathobiol., Addis Ababa Univ., 1982,15-28.

Gemetchu T. and G.K. Fuller. Kala-azarin Ethiopia: the phlebotomid sandflies of the Awash river valley. Ethiop. Med. J., 1976, 14, 2, 81-85.

Gemetchu T., G.K. Fuller and A. Zarihune. Kala-azar in Ethiopia: Sandflies (D iptera: Phlebotomidae) of South-west Ethiopia. Ethiop. Med. J., 1976, 14 2, 73-80

Gemetchu T., A. Zarihune, G. Assefa and A. Lemma. Observations on the sandfly (Phlebotomidae) fauna of Setit-Humera (North western Ethiopia). Colloques intern, du C.N.R.S. N 239, 1974, Paris. 1977, 207-212.

Gemetchu T., A. Zarihune, G. Assefa and A. Lemma. Observations on the sandfly (Phlebotomidae) fauna of Setit-Humera (North western Ethiopia). Ethiop. Med. J., 1975, 13, 2, 41-51.

77 Haile T. and A. Lemma. Isolation of Leishmama parasites from Arvicanthis in Ethiopia Trans Roy. Soc. Trop Med Hyg 1977, 71t 180-181

Hebte-Gabr E. Visceral Leishmaniasis (kala-azar) clinical features In: Leishmaniasis in Ethiopia: a handbook Proc of Workshop, 25-27 May 1981, Inst Pathobiol , Addis Ababa Univ 1982,41-44.

Houin R„ J.C. Basin and J. B o lg n im . Etudes des leishmaniases dans la vallee de I'Omo (Ethiopie). I. Recherch d un reservoir de vir js sauvage Rev pathol. compare, 1968,68, N 799, 361-363.

Jembere S. Bnef regional repors on leishmaniasis in Ethiopia Gondar Region. In Leshmaniasis in Ethiopia a handbook Proc erf Workshop, 25-27 May 1981. Inst. Pathobiol.. Addis Ababa Univ.. 1982. 67-71

Le Blancq S.M. and W. Peters. Leishmania in the Old World 4. The distribution ot L donovani sensu lato zymodemes Trans Soc. Trop Med Hyg.. 1986, 80. 1 367- 377

Lindtjom B. Kala-azar in Sidamo. South Ethiopia Ethiop Med. J., 1980, 18, 3, 99-100.

Lindtjom B. Visceral Leishmaniasis in the Dawa valley, south Ethiopia. Ethiop. Med J.. 1987, 25, 4, 211- 212

Lindtjom B. Bnef regional reports on leishmaniasis in Ethiopia. Gamo-Gofa Region. In: Leishmaniasis in Ethiopia a handbook Proc of Workshop. 25-27 May 1981, Inst Pathobiol.. Addis Ababa Univ., 1 82.

Lindtjom B. and J. Olafsson. Kala-azar in the Seggen and Woyto valley. South-west Ethiopia. Ethiop. Med J.. 1983. 21. 1. 35-42.

Maru M. Clinical and laboratory features and treatment of visceral leishmaniasis in hospitalized patients in northwestern Ethio pia. Am. J. Trop. Med. Hyg., 1979, 28.15-18.

Marzo de V. Studi di Medicina Tropicale. 1914 (cited by Bucco) L’organizzazione sanitaria in Africa orientale L'ltalia in Africa. Serie Civile, 1965. 1-3.

Mengesha and M. Abuhay. Kala-azar among labour migrants in the Metema-Humera region of Ethiopia. J. Trop. Geogr Med.. 1978. 30. 199-206

Omran A.R. The ecology of leishmaniasis Studies in disease ecology. Ed May J.M., New York, 1961 331-388

78 Parrot J. Notes sur les phlebotomes. XYII. Phlebotomes d'Ethiopia Arch Inst. Pasteur Algerie 1936,14, 30.

S ch a ller K.F. Ethiopia In Geomedical Monograph Series Ethiopia Ed. Hefmut J. Jusalz. Springer- Verlag. Berlin-Heidelberg-New-York 1972. 101-102

Schaller K.F. Epidemiologie der Leishmaniasis in Athiopien Bull Phanm. Res. Inst.. 1973, N 100. 48-54

Southgate B.A. and D.M. Minter. Leishmaniasis and its control in Kenya: the present situation WHO/LEISH/INF/67 4

Tekle A., P. Neri and Dedessai. Kala-azarin Humera (North-wesVEthiopia). Parassitologia, 1970, 12, 21-28.

WHO. Control of the leishmaniasis. Repoit of a WHO Expert Committee, Technical Report series 793 1990.

WHOTTDR/Leishwswg (3)/81.3 Epidemiology of the leishmaniasis: report of the third meeting of the scientific working group on leishmaniasis. 41 p.

79 TERMITES AND THEIR INFLUENCE ON SOIL COVER FORMATION IN BARO-AKOBO INTERFLUVE

Abaturov B.D., V.V.Sizov, and L.B. Rybaiov

It is well known now that the role of termites in ecosystems is quite diverse. Digging activities and nourishing peculiarities of these insects enable activation of material cycle. Soil and microrelief changes, and as a result of it invoke modification of hydrological regime of the territory (Dakushev, 1968; Boyer, 1969, 1973, 1975; Hesse, 1955; Lee, Wood, 1971 a. b; Wood, Sands, 1977, etc). Penetration of routs through the soil thick­ ness and transportation of soil material of different chemical composition which occurs In construction of termite hills are leading to interruptions in natural soil composition, changes of their structure, physical and chemical properties, and influence the soil formation process as a whole - formation of the soil cover of dry savanna. We shall try to assess the scaie and character of this phenomenon having studied the example of one of the regions situated in sub equatorial zone of Africa, where termites activity is extremely intensive.

Our researches were conducted In the dry season of 1986-87 on the watershed of Alvero and Nicani rivers (Baro-Akobo Interfluve, Illubabor administrative region southwest Ethiopia). The studied site is a closed drainage area with numerous micro depressions. Soils are chromic vertisols in complex with brown siallitic savanna soils. Dark vertisols occur in microdepressions. Most of the territory is annually flooded during the dry season and the soils convey dear features of paleo or contemporary

80 hydromorphism. Vegetation consists of scarce forest with domination of Combretum sp., Dafbergia boehmii, Balanites aegyptiaca, Acacia spp, and Gramineous high grass land (Hyparrhenia sp., Beckeropsis sp., Vetiveria sp., etc.). By the end of vegetative season Gramineae are reaching a height of 4 m., the above ground phytomass at this time exceeds 1.5. Kg/M2 (dry weight). Every year the dry grasses are burned down by native population.

Materials and methods

In the boundaries of the studied region termites were enumerated. There were analyzed the morphological and some chemical soil properties as well as particle size distributions in undisturbed soils and in soil material constituent of above and underground parts of termite hills. Systematic pertinence of termites was also identified. Four testing plots, 1 ha each, were selected for estimation of termite hills abundance and of the area they occupy. Average was measured between neighbour hills, diameter and height of each hid was measured on every testing plot. Number of termite hills per testing plot was calculated according to the following equation:

N = S/12

where: N - number of termite hills on testing plot, S (sq. m) - area of the plot, 1 (m) - average distance between neighbouring termite hills (Abaturov, 1984),

The average area occupied by a single termite hill and their summary area was derived from the foundation diameters (tab. 1).

81 Table 1. Number and spaciousness of termite hills in the high grass savannas (meantS.E.)

Total area of termite hills. (m:)

Plot No Number of Height of Foundation Foundation Distance between Number of

measurements termite hill, diameter, (m) area. (m:) neighbour termite termite hills

(m) hills, (m) per ha m: % of plot area

1 25 1.2 ±0.13 8.5± 0.32 570 2? 5 ± 2.02 13.2 755 7 5

2 19 1.3 ± 0 16 7 3 ± 0.52 41.4 32 1 ± 3 09 9 7 401 4 0

3 21 1.7 ±0.19 8.4 ± 0.57 56.4 28.9 ± 1 87 12.0 675 6.7

4 21 2 1± 0 17 8 2 ± 0.55 52.7 38 4 ± 2 37 6.8 357 3.6

Average 1 6 ± 0 09 8.2 ±0.24 52.1 31.5 ± 1.23 10.0 ± 1.41 526 5.2 ± 0.97 Content of particle, %• Pit No Depth, cm Air-dry moisture, % 1-0.25 0.25-0.05 0.05-0.01 0.01-0.005 0.005-0.001 <0.001 Total Total <0.01 ' >0.01 190-200 5.0 9.0 2S.8 9.1 4.4 14.1 37.6 56.1 43.9 Jt 140-150 4.2 7.8 32.2 10.1 4.6 10.0 35.5 49.9 50.1 90-100 5.0 10.7 23.6 12.7 7.8 S.9 39.3 53.0 47.0 Termite hill 70-80 5.3 10.3 10.0 20.6 4.7 14.4 40.0 59.1 40.9 arial part 50-60 5.8 9,5 18.7 8.4 I I . 1 2.4 49.9 63.4 36.6 30-40 5.7 9.7 21.5 13.4 2.) 18.5 34.8 55.4 44.6 10-20 7.0 9.4 30.5 9.5 2.6 15.1 32.8 50.5 49.6 30-40 4.4 9.6 20.1 12.3 8.6 7.4 42.0 58.0 42.0 50-60 6.2 8.8 18.3 16.6 1.2 14.0 41.0 56.2 43.8 70-80 6.6 9.1 16.9 15.5 6.4 8.2 44.0 58.6 41.4 Termite hill 90-100 7.6 4.2 23.0 11.2 5.6 14.4 41.7 61.7 38.3 130-140 5.4 18.9 . pari 2.9 9.2 7.2 13.3 48.6 69.1 30.9 170-180 5.6 2.6 23.6 16.6 0.1 13.2 43.9 57.2 42.8 0-10 8.6 2.3 4.4 14.4 4.3 18.4 56.2 78.9 21.1 31 10-20 4.4 8.1 24.2 18.7 2.1 13.6 33.2 48.9 51.1 Undisturbed 30-40 4.0 5.6 33.5 13.8 8.2 7.1 31.8 47.1 52.9 soil 90-100 5.2 2.8 16.4 11.4 7.8 15.1 46.5 69.4 30.6 110-120 6.6 1.1 4.2 21.9 5.8 11.7 55.2 72.7 27.3

Height for aerial part of termite hill, cm

Table 3. Chemical properties of the soil material of termite hill and of undisturbed soil.

83 Soil profile Depth Humus, pH exchange base, mg-eq/100 g Mobile nutrients, mg/100 g C02 cut (heighO.sm % hydric % carbonale Ca Mg Na K Total P ,0 , KjO 190-200 1.4 6.6 19.2 8.1 I.l 0.6 29.0 .. 0.1 11 140-150 1.2 6.6 15.1 7.3 1.4 1.2 25.0 02 <10-100 0.7 7.0 16.3 7.3 1.5 1.0 26.1 0.2 Termite hill 70-80 I I 7.4 19.5 7.9 2.2 Ttf.A . 0.2 arial part 50-60 1.1 7.8 18.0 7.9 2.4 0.6 289 15.5 9.0 0.1 30-40 1.0 7.8 23.2 8.7 2.7 0.6 35.2 24.7 7.3 0.1 10-20 1.2 7.8 26.7 10.7 3.5 0.6 41.5 16.5 0.2 10-20 0.9 7.7 30.1 10.9 2.9 0.4 44.3 0.3 30-40 Termite hill 1.0 7.6 27.6 9.8 4.0 0.3 41.7 0.2 50-60 0.9 7.4 underground 19.8 8.7 2.7 0 J 31.5 0.2 pari 70-80 0.8 78 25.9 9.3 3.1 0.4 38.6 0.3 90-100 1.2 7.9 30.2 124 3.9 0.5 47 0 0 4 130-140 0.6 8.0 33.4 11.3 3.9 0.4 490 0 4 170-180 0.6 8.0 25.8 11.1 0.3 40.7 0.3 10-20 1.4 6.6 11.8 6.2 1.0 0.3 19.3 30-40 i.l 7.0 13.7 7.8 18 0.3 23.6 . 21 50-60 1 1 7.1 14.6 7.8 3.0 0.4 25.7 90-100 0.5 7.6 20.2 9.7 4.2 0.4 34.5 . . 140-150 0.4 7.9 28.0 12.1 4.7 0.4 45.2 0-10 1.9 6.1 9.2 4.6 0.4 0.2 14.4 6.4 16.8 Non 10-20 v 1.7 6.1 3t 9.4 6.2 2.0 0.2 17.8 2.6 4.5 Non W-40 0.8 68 8.8 Undisturbed 5.7 2.0 0 1 16.7 3.9 13.0 Non 90-100 0.7 7.9 soil 23.1 12.1 5.0 0.4 40.6 0.1 110-120 0.7 7.9 22.9 11.2 4.9 0.4 39.3 Non

84 To study the constitution of termite hill and properties of composition of its material a vertical cut was made through the center of a medium (2.5 m high) hill 2 m down Into the sol) (pit It ). Out of termite hill fcvo more pits (1.5 m deep) were set in line. Pit 2t was made at 5m distance from the hill center and pit 3t was based on undisturbed soil 1 1 m away from the hill center. Samples were taken every 20 cm from the vertical section of the termite,^illl (up to 2 m high) and from soil profiles (up to 1.5 m deep) to determine some chemical parameters and particle size distribution. Samples were taken In. respect to genetic horizons in profile 3t. Simultaneously termites were sampled for systematization.

R esu lts

Two species of Termitidae family prevailed in the high grass savanna with rare trees on vertisols. They were Trinervitermes oeconomus and T. gratious2. Trinervitermes oeconomus (Jragardth) is a widely spread eurybiontic termite species which ranges from Sudan to Ghana (Sands, }965). It inhabits a number of different subzones from savanna forests to desert savanna of Sahel and goes into deserts of Sudar^ Termites of that species were collected from big termite hills (up to 3.5 m high). Trinervitermes gratiosus (Sjostedt) is also a typical species of African savanna, but has a smaller area (Sands, 1965). It is one of the mass species of savanna forests (key et al., 1965) spread almost to the border of rain tropical forests and is allocated to plots with gramineous vegetation. These termites were sampled from termite hills less then 1 m high.

2Authors express their gratitude to N.V. Belyaeva for systematic ’dentification of termites.

85 Termite hills created by Trinervitermes oeconomus are a characteristic landscape element of high gramineous savanna and provide for its spedflc image. Average height of hills Is 1.6+0.09 m, maximal is 3.5 m; average foundation diameter is 6.1+0.24 m, maximal Is 15 m ; average area of foundation is 52 sq. m. Average distance between neighbour termite hills which reflects their abundance, was found to be from 27.5 to 38.4 m according to measurements made on four testing plots. Number of hills varied from 6.8 to 13.2 hills per ha, 10.0+1.41 h/ha as an average. The total percentage by area of termite hills ranged from 3.6 to 7.5% of plots area, as an average 5.2+0.97% (tab. 1). Thus the termites constructions occupy sufficiently big area in the studied region and exert considerable influence on the environment.

The soil profile 3t is typical for chromic Vertisols that are found here (fine calcareous, moderately sodic, low humus, fine vertic, heavy textured) and are characterized by dark brown colour of upper horizons which is getting lighter with depth.

Starting from 15-20 cm they are very compact and reveal vertic properties like cracks throughout the profile. Starting from depth of 20-30 cm hydromorphic properties like rusty ochric iron and manganeses mottles are identified. The profile is stretched but distinctly differentiated into genetic horizons. A calcic horizon Is found at 83 cm. Carbonates are represented by abundant soft powery forms and isolated concretions. The soil effervesces with 10% HCI in places of soft powdery carbonates accumu­ lation and at calcareous mettles.

86 As a result of termites digging activities the soil profile is becoming homogeneous, not differentiated into genetic horizons. Structure becomes more loose and porous with less cracks, all the big crumbs and blocks are cut by pores (termite routs). However all the soil mass is solidly cemented by excrements and termites saliva that is why one can brake the material of a termite hill only with a pick. Such a porous and cemented structure has high water penetrability .and water stability. The carbonates are more evenly distributed in the profile under the termite hill then in undisturbed soils. Rare calcareous pseudomicelium effervesce from 30 cm maximal accumulation of carbonates in form of alluvial calcic horizon is found at 140 cm.

The soil profile 2t is also homogeneous and not divided into genetic horizons.

Thus termites induce considerable changes to soil profile morphology not only in the center but in the whole area of termite hill foundation.

Soil texture is also changed due to termite activity. According to some data (Boyer, 1975) originally sandy and clay soils become loamy. Our observations also showed that the texture of soil mass modified by termites becomes lighter in comparison to initial undisturbed soil which is characterized by uneven particle size distribution. Clay content (tab. 2) in surface horizons of undisturbed soils is reaching 56.2% and decreases with depth to 31.8-33.2% and increases again to 46.5-55.2% at the depth of 100-120 cm. Fine sand content varies from 4.4 to 33.5% and that of physical clay decreases from 79.0 to 47.1% in the middle part and increases again to 69.4-72.7% in the lower part of profile. As a whole this soil varies in texture from medium clay to heavy loam. The texture of termite hill soil Is more uniform then that of the undisturbed one. Clay fraction content in the aerial part varies between 32.8 and 49.9% with a maximum in the central part of the hill at the elevation of 50-60 cm and a minimum - at the foundation at the elevation of 10-20 cm. Fine sand and physical clay content change respectively in the boundaries of 10.0-32.2% and 49.9-63.4%. Particle size distribution in the underground part of the termite hill is also sufficiently uniform. Clay content varies from 41.0 to 48.6%, that of physical day-from 56.2 to 69.1% In the Initial undisturbed soil average day content (44.6%) is relatively lower then in the underground part (43.5%) and higher then In aerial part (63.4%) of the termite hill.

Soil texture of underground part of the termite hill is heavier (light clay), then that of the aerial part (heavy loam).

The data of soil material analysis available in literature testify to momentous changes of soil chemical composition, particularly to increase of carbon, nitrogen, phosphorus, potassium, calcium etc. (Hesses, 1955; Lee, Wood, 1971; Pomeroy, 1976 a, b; Sys, 1955; Trappnell et al., 1976; Watson, 1966).

Our data show distinctive difference in humus content in soil material of termite hill and undisturbed soil (tab. 3). Humus content Is rather high (1.7-1.9%) In upper horizons and constantly decreases with depth (to 0.7-0.8% at 110-120 cm) in initial undisturbed soil (vertlsol of dry savanna). The soil material of termite hill contains less humus then the initial soil but its distribution in the profile is more even. Humus content in the underground part varies from 0.8 to 1.2% with a maximum at the depth of 90-100 cm. In

86 the aerial part It varies from 0.7 to 1.4% with a minimum at the elevation of 90-JL00 ari and a maximum at the top of the termite hill (approximately at 200 cm). Average humus content in the underground and aerial parts of termite hill Is almost the same and amounts to 0.9 and 1.0-1.1% respectively. Thus termites change the humus profile of Initial soli, make It uniform, slightly decreasing humus content in the upper part and increasing it In lower layers of soil profile. Termites also hoist humus to aerial part of termite hill where It is equally distributed throughout the hill's height.

Humus content in profile 2t Is relatively lower then In undisturbed soil but the distribution Is the same. Evidently the Influence of termites on adjoining areas is limited to the upper (20 cm) layer, where a noticeable decrease of humus occurs. Humus content In upper horizon decreases In the dlretfion from the undisturbed soil to the center of the foundation of the hill from 1.9% at 11 m from the center to 1.4% at 5 m distance and to 1.2% in the center (tab. 3). .

PH of the upper horizons of undisturbed soils is slightly, add (6.1), deeper it Is neutral and slightly alkaline (S.9-7.9). In the termite hill the pH values are higher (advanced into neutral and alkaline area) and almost equal. However In the underground part they are a bit higher then In aerial one. pH value at the top ,of the hill (6.6) Is associated with leaching role of precipitation.

Mobile phosphorus content in the aerial part of termite hill (15.5 - 24.7 mg./100g of soil) is significantly higher and that of mobile potassium (7.3 - 9.0) is significantly lower then in undisturbed soil.

89 Percentage of carbonates In the soli material of termite hill ranges from 0.1 to 0.4%. Their content in aerial part Is lower (0.07-0.23%) then In the underground part (0.18-0.41%). The analysis did not reveal carbonates In the undisturbed soil (except for the 90-100 cm layer).

Content of exchangeable cations (excluding Na) Is rising In the direction from undisturbed soil to the center of termite hill foundation. The content of exchangeable Ca in the aerial part of the termite hill amounts to 15.1-26.7 mg-eq./lOO g of soil, in the underground part it takes values of 19.8-33.4; the contents of exchangeable Mg is respectively 7.3-10.7 and 8.7-11.3; and that of exchangeable K is respectively 0.6-1.2 and 0.3-0.5 (tab. 3). The content of exchangeable Na is the ;ame as In undisturbed soil. The total amount of exchangeable cations (25.0-49.0) Is also higher then in the undisturbed soil (14.4 - 40.6) furthermore it is lower In the aerial part of the termite hill then in the underground one. The percent ratio of exchangeable Na to total amount Of exchangeable cations is 3.8-9.6% in the termite hill material and 5.2-12.2% In the soil at the foothill of the teimlte hill (profile 2t) while It Is 11.2-12.5% in 'I. ' the undisturbed soil (profile 3t). These data demonstrate that the increase of total amount of exchangeable cations from undisturbed soil to the center of termite hill leads to lowering of the rate of solonetz processes. To put It in other way, the soil becomes less solonetz - like as a result of termites activities. In the undisturbed soil (p. 3t) and in the soil at the hill foundation (p. 2t) one may clearly observe a distinctive accumulation of soluble salts in the lower soil layers (deeper then 100-150 cm) which Is quite characteristic for chromic Vertisols. The contents of HC03 ion is rising from 0.2 at 0-10 cm to 0.86-0.91 mg-eq./lOO g at the depth of 100-120 cm and that of Na grows from 0.1 to 0.86 mg-eq./lOO g. The salt content changes insignificantly in the underground part of the termite hill: from 0.65 to 0.80 mg-eq./lOO g as to

90 Na; in the aerial part it decreases from foundation to top and has a wider range of fluctuations: from 0.72 to 0.19 mg-eq./lOO g of HC03 ion and from 1.44 to 0.22 mg~eq./100 g for Na ion. The soil material of termite hill as a whole contains more soluble salts then the initial soil. Thus the average salt content in the termite hill in 0-40 cm later is higher (HC03-ion-0.78; CI-ion-0.13; Na-ion-0.75 mg-eq./lOO g) then in the undisturbed soil (respectively 0.21; 0.08; 0.21 mg-eq./lOO). As to the 0-100 and 0-200 cm layers In aerial and underground parts of the termite hill the salts content there is also higher then in the undisturbed soil. Solely the content of K-ion is virtually the same in termite hill and undisturbed soils. The content of soluble salts in the 0-40 cm layer of profile 2t (HC03-ion-0.22; CI-ion-0.08 and Na-ion-0.24 mg—eq./lOO g) is equivalent to that in undisturbed soil.

Thus the termites activities interfere with initial salt profile differentiation. Since the soil of the plot situated at the foundation of the hill and the undisturbed soil contain lesser amount of salts one might presume that termites are brining up to the surface salt enriched soil material from deep layers (under 150 cm) of the central part of termite hill and not from the surface of surrounding area. Besides the termite hills serve as peculiar taper which pull up the vertical flows of mineralized soil solutions from deep horizons and horizontal flows from the areas surrounding the termite hill. These processes of salt migration are most intensive in the wet period when the land around the hillocks is partially flooded.

Termites are significantly changing the microrelief of the territory they inhabit. The termite Trinervitermes oeconomus activity in the watershed of Alvero and Nicani rivers results in complication of initial microrelief (flat plain with multiple saucer like depressions) by abundant termite hills up to 3.5 m

91 high. Our observation! show that the termite hills after their expiration and destruction are replaces by microelevations which enact as drained Islands in the territories flooded in rain season and provide for development of tree growth, Balanites aegiptlca, for example. It was noticed earlier in other African savanna, which experience seasonal flooding.

Diagnostic features of vertisols as a type: presence of mulch layer, slickensides, cracks etc., and also on family and group levels: carbonates and salts content, texture etc. are getting partially vague irw.the soils of termite hills. According to some appraises the changes found in the soils of termite hills happened In approximately 20 years. Bearing In mind that the age of termite hills may extend to 80-100 years one is to expect much more noticeable changes of composition and properties of the soils of termite hills.

Termite hills are the limit structural elements. They are complicating the soil cover structure and increase its diversity and complexity

Putting into work of a project of agricultural development of the territory with such a complicated soil cover calls for essential conduct of leveling measures, f It is necessary to take into account that complexity of soil cover makes It difficult to use this territory in the designated crop rotation system with irrigation. It Is indispensable to use large scale and detailed soil survey using key maps and catena methods for mapping soils of this territory. Since the soil material of the aerial parts of termite hills is not worse then that of the surrounding soils as to chemical composition and is even better by some parameters we recommend not to transfer the material of the destroyed hillocks from the fields but to use It for but to use it for filling microdepressions. Evidently the soluble salts contained in big quantities in the material of termite hills will be washed down into lower horizons by plentiful rains of the wet seasons.

REFERENCES

: Abaturov B.D., 1884, Mammals as a component of ecosystems, (in Russian) Moscow. Nauka, 285 p.

Boyer P. Les effects de I'implantation des termitieres des bellicositenmes sur la configuration des sols des savanes de la Republique centrafricaine. Bull. Mus.nath. Hist. Nat., Paris, 1969, 41 3, 789-800.

Boyer P. Action de certains termites constructeurs sur revolution des sols tropicaux. Ann. Sci. nat., Zool. et Biol. Animal, 1973, Ser. 1 2 ,I jj 329-498.

Boyer P. Les differents aspects de I'action des belliconsistermes sur les sols tropicaux. Ann. Sci. nat.. Zool. et Biol. Animal 1975,1Z 447-503.

Hesse P.R. A chemical and phisical study of the soil of termite mounds in East Africa. J.Ecology, *1955. 43 449-461.

Josens G. The soil fauna of tropica) savannas. IIJ. The Termites. In. ecology of Tropical savannas, • Springer-Verlag, Berlin - Heidelberg - New York, 1982, 2 505-52 4

Keay R.W.J. Vegetation map of Africa south of the Tropic of Cancer. Explanatory notes. 1 map. Oxford Univ. Press. New York, 1959, 24 p.

Lee K.E., Wood T.G. Termites and soils. London - New York, Acad. Press, 1971 a, 251 p.

Lee K.E., Wood T.G. Physical and chemical effects on soil of some Australian termites and their pedological significance. Pedobiologia, 1971 b, Bd. 11, 5, 376-409

Pomeroy D.E. Some effects of mound-building termites on soil in Uganda. J. Soil. Sci., 1976 a, g7, 3, 377-39 4

Pomeroy D.E. Studies on population of large termite mounds Uganda. Ecol. Entomol., 1976 b, 1 , 1, 49-61

Sands W.A. A revision of the termite subfamily Nasutitermitinae (Isoptera, Tenmitidae) from Ethiopian region. Bull. Brit. Mus. (Nat. Hist.), Entomol., Suppl. 4, London, 1965, 172

93 Sys C. The importance of term tes in the formation of latosols in the region of Elisabethville. Soils Afr., 1955.3, 393-395

Trappnell C.G., Friend M.T., Chaberlain G.T., Birch H.F. The effects of fire and termfrtes on a Zambian woodlands soil. J. Ecd.. 1976, 64, 2, 577 -5 8 8

Watson J.P. The soil below at termite mound. J Soil S ci. 1966. 1 3 .4 6 -5 1

Wood T.G., Sands W.A. The rote of termites in ecosystems Production Ecology of Ants and Termfites Ed. Brian M.V., Cam br, Univ P ress, Cam bridge, 1977. 2 4 5 -2 9 2

Yakushev V.M., 1986, On influ ence of vital activity of termites on the formation of lateritic cover. (In Russian) Pochvovedenie, No 1, p. 113-115

94 SOIL COVER OF THE BARO-AKOBO INTERFLUVE

Sizov V.V.

Soils of tropical zone are the most ancient on the Earth. Their formation Is determined by a number of intensive consecutive stages of weathering and soil formation, such as alkaline hydrolysis of primary minerals with subsequent rapid removal of earth elements; destruction of mineral framework and release of silicon, iron and aluminum, intensive migration of different iron oxides in the soil profile and also aggregation of mobile iron oxides in the form of numerous concretions.

Baro-Akobo interfluve belongs to subequatorial dry subzone of tropical zone (with dry season lasting about 6 months), where processes of weathering are weaker than in humid tropics. The release of iron, aluminum and silicon takes place during the wet season, moreover, silicon is not leaching intensively, but interacting with aluminum, forms kaolinite and illite clays. During the long dry season siallitic process is taking place, leading to formation of illite-montmorillonite day types and to formation of vertisols. The above-mentioned processes lead to formation of the main soils in the Investigated area, which spreads from South-western slopes of Ethiopian highlands to vast South Sudan plain; red ferallitized (nitosols), ferruginous tropical (red-brown) soils, brown siallitic savanna soils, vertisols, planosols.

The climate of interfluve is tropical monsoon with two highly diverse seasons. The wet season lasts from May till October (more than 85% of the total annual precipitation); the dry one, from November till April. The total

95 annual rainfall decrease? from South-Western slopes of Ethiopian highlands (1300-1500 mm) to South-Sudan plain (800-900 mm). Average monthly temperature varies fron + 26°C to + 30,2°C during the year; absolute minimum is + 10,3°C, absolute maximum is +47°C. Average long-term total temperature, according to Gambela city meteorological station data, is 10150°C; 5220°C during the dry season, 4930°C In the wet season. Average monthly data for air humidity vary from 45-48% in the dry season to 60 - 70% - in the wet season. Maximal evaporation is 181-189 mm per month during January-Aprll, and minimal is 81-97 mm per month during June-August. In comparison with the highlands the climate of the plain is notably more arid, gradually Increasing to the West.

As far as geomorphology is concerned, investigated territory is a transitional zone from the South-Western slopes of Ethiopian highlands to the South-Sudan plain (Sudan Geslra). Steep South-West slopes of Ethiopian highlands are strongly dissected by deep narrow Incised valleys of the main rivers and their numerous tributaries. Absolute heights at short distance vary within the wide limits from 1700 to 700 m. High foothill plains, low and flat accumulative plains are Identified. High foothill plain Illubabor Is characterized by low knob-rolling denudative-accumulative relief with gradual lowering to the West. Absolute heights vary from 500 to 700 meters. Low plain Illubabor Is accumulative plain composed by alluvial cone trains complicated by numerous closed pateloid microdepressions, dead river channels, temporary run-off hollows. Average absolute height is 425-500 m. In the Western part there begins the flat water-aggraded South-Sudan plain, overmoistured or flooded during the rain season.

06 Quaternary sediments, genetically bound with geomorphological forms of relief and Its elements are widely spread over the investigated territory. Within the bounds of the high Illubabor plain, on the wide flat low-hill crests alluvial deposits are spread, alluvial-deluvial deposits are spread on the ravine slopes within the boundaries of low Illubabor plain. Quaternary al- /uvial-deiuviai-proluvial sediments with the thickness not more than 20 meters^re represented by shingle beds, days and loams with inclusion of .Shingles and gravel. Flat water-aggraded plain is infilled by facustrine-aliuvial deposits. Vast areas along hydro-graphic network almost every-where are formed by present alluvial sediments, represented by loams, clays, loamy sands and sands.

Two water-bearing complexes are defined on the territory according to hydrological conditions. The first is connected with Upper and Middle Pliocene and Quaternary loose, often alternating sandy-loamy-clayey and gravelly sediments, and is developed all over the territory of the low Illubabor plain. Pliocene clayey rock-bench in Alvero sandstone and clay strata forms a regional water-impermeable basement. Feeding of this complex by precipitation is practically impossible and is realized by pouring of water from High Illubabor plain water-bearing complex and unloading of Baro, Alvero, Gilo and Akobo rivers. Ground water flow jn the complex is directed from the river beds deep into watershed with the slope of 0.01-0.005 all the year through and has the concave surface.

The depth of ground water is 20-30 meters on the high foot hill plain; 10-20 meters on the low plain. The flat accumulative plain is characterized by gradual increase of the ground water level from 20 to 3 meters. In the flood plain and scroll territories of the big rivers ground water table is 1-5

97 meters. Seasonal variations in the ground water level are practically absent, mineralization is negligible, and accounts for 0.2-0.8 g/l. The second water­ bearing complex is connected with joint zone of Pliocene rocks, represented by Gog basalts. Its ground waters are confined and alimentation is realized by ouring of water from water-bearing complex of the high Illubabor plain.

The plain territory belongs to the formation of weakly acid and neutral soils of dry tropical climate. Brown siallitic savanna soils, planosols, vertisols are identified. Soils of foothill plains and slopes of Ethiopian highlands belong to formation of allithic and ferallitic acid soils of humid tropical zone with short dry season. Here ferruginous tropical soils have been formed. On the plateau-shaped crests of the Ethiopian highlands ferallittzed red soils have been formed.

Ferallitic crusts of relict genesis are widely spread over the investigated territory and represent very compact conglomerate, consisting of iron-manganese concretions with fragments of shingled-gravelly material (quartz, feldspars) and filled by loamy-clayey mineral mass.

The following soil types were identified on the soil map with the scale of 1:200 000, compiled for the Scheme of Complex Use of Water and Soil Resources of the Baro-Akobo interfluve: red ferallitized, (nitosols, according to FAO) (Soil nomenclature, 1974); ferruginous tropical (red-brown ferallitic savanna); brown siallitic savanna, according to J.L.D'Hoore - brown eutrophic tropical (Soil map... 1974); vertisols, planosols (according to FAO); meadow-marshy, alluvial, lithosols. Taking into account the lack of knowledge and the scarceness of publications on soils of the North East Africa and, especially, of Ethiopia, following materials were used for working

98 out nomenclature for soil types: legend to the Soil Map of the world 1:10 000 000 edited by V.A. Kovda (1975); legend to the Soil Map of the World 1:500 000 FAO/UNESCO (Soil Map of the World, 1974) and also publications of B.G. Rozanov (Soil nomenclature, 1974), B.G.Rozanov et al. (1982; 1983), S.V. Zonn (1985), V.V. Ivanov et al. (1985).

Let's examine some features of these soils.

Ferallitized dried soils are spread in the North-East and East parts of the foothill knob-ridgy medium-dissected plain of Ethiopian highlands; absolute heights are 1400-1600 meters. They have been formed on exuvial-sediments with inclusions of weathered rock fragments beneath seasonally-humid mountain tropical forests, that nowadays are practically cut down and are replaced by secondary savanna.

Their characteristic features are: bright red colour of the whole profile, high thickness of the soil profile with dark-grey well-structured humic A-horizon, good water-proof fine pseudo-sandy (subangular) structure, dependant on high content of free aggregated iron oxides in the form of microconcrations; full lack of carbonates and ready-soluble salts, lack of compacted horizons.

As far as their chemical properties are concerned, soils are characterized by high content of humus (2 .0 -1 0 .5% ), acid reaction of soil solution in the whole profile (pH 4 .2-4 .4 ); high values of exchangeable acidity (3.7-5.1), hydrolytic acidity (10.2-18.7) and exchangeable hydrogen

99 (3.8-12.1 mg/eq/100 g). Soils are acid and unsaturated in bases. Soil texture is heavy-loamy and clayey.

Ferruginous tropical soils (red-brown fersiallitic savanna soils) are spread in the East and North-East parts of investigated area on the high foothill denudative-accumulative rolling plain with absolute heights of 450-650 meters. They have been formed on deluvial-proluvial deposits and partly on laterite, as a rule, under deciduous xerophytic forests. These soils are characterized by red-brown colour of the whole profile with numerous bright brick-red mottles and with greyish-dark-brown a horizon; accumula­ tion of iron throughout the whole soil profile, resulting in formation of iron manganese concretions 2-7 mm in diameter; good water-proof structure, caused by high content of free aggregated iron oxides, lack of compact water-impermeable horizons, widely spread ferallitic crusts, situated closely to the soil surface. The content of humus is high, but it is lower than in red ferallitized soils (1 .0 -5 .3 % ); acid and weakly acid reaction of soil solution in the lower part of the profile and nearly neutral in the top-soil (pH 4.6-7.0). The values for hydrolytical acidity (1.3-6.2 mg-eq/100 g) are not high, exchangeable cations content decreases rapidly with depth (8.7-24.5 mg-eq/100 g) (Table 2). Soils have clayey texture. Minimum content of silt (26%) and at the same time high values for hydrolytical acidity (5.5-6.2 mg-eq/100 g) at the depth of 10-20 cm are observed; simultaneously silt content in the lower part of the soil horizon is increasing (38.1-43.9%). Therefore one can suppose that the processes of lessivage are taking plare here and ferruginous soils are lessivated to some extent.

Brown siallitic savanna soils occupy mainly flat water sheds of low accumulative plain. Absolute heights are 425-550 meters. These soils have been formed on alluvial-proluvial sediments and, partly, on laterite. Ground waters don't participate in soil-formation process, because of their depth, which, is 10-30 meters and deeper. Formation of brown siallitic soils in BarorAkobo interfluve conditions is connected, on the one hand, with auto- morphlc siallitic process, on the other hand-with surface hydromorphic process, Caused by annual soil over-saturation with rainfall and flood waters. The first process results in low content of humus, partial carbonatization of the lower horizons; the second one results in high content of free sesquloxides,'especially in the lower horizons, in the form of bright mottles, concretions.

It should be mentioned, that all the automorphic soils of low Illubabor plain are subjected to surface hydromorphic influence. The degree of soil hydromorphism is Increasing from light, and therefore more drained soils with concretions, to heavier ones sometimes having signs of gleying in*the lower horizons.

The characteristic features of these soils are: light brown colour, distinct differentiation of soil profile into genetic horizons, lower, than in ferruginous tropical soils, concentration of free sesquioxides (R 2O3) in the form of rusty Iron manganese mottles and concretions, sandy texture of the upper horizons. Their properties vary deeply from the two already mentioned soil types and they belong to neutral and alkalescent ones. They are characterized by low humus content (1.0-2.8%), decreasing rapidly down the profile, small amount of exchangeable cations (5.5-10.4 mg-eq/100 g); exchangeable Ca2 + prevail upon exchangeable Na+ and Mg2-+; weakly acid and neutral reaction of soil solution in the upper horizons and alkalescent reaction in the lower horizons (pH 6.2-8.0). The soils are neither saline nor

101 — ■ ■' ~ • 1 5 . U * '

sodic. However, there are some clayey soils with increased content of exchangeable Na* (2.4-3.5 mg-eq/100 g), and water-soluble Na* (0.6-0.9) and HC03-ion (0.9-1.2 mg-eq/100 g) in the lower horizons. Such brown siallitic savanna sodic soils were identified in the framework of the "Alvero" project. As usual, these soils are potentially saline at the same time.

Among brown siallitic savanna soils, solod soils can be found. They are notable for their well-defined binary profile with coarse texture in the upper part and fine one in the lower part of the profile, and also by signs of solod process under Al horizon in the form of whitish spots or entire whitish A2-horlzon.

Vertisols are usually spread in the Western part of the interfluve on the flat accumulative plain with numerous patellold microdepressions. Their area is the biggest one-nearly 43% of the investigated territory. Absolute heights are 405-500 m. Chromic vertisols are spread on slightly raised territories of the flat plain; dark vertisols have been formed in more hydromorphic and less drained conditions and are connected with low ele­ ments of microrelief depressions, dead river channels). Alluvial - lacustrine sediments with clayey texture are the parent material.

As a rule, vertisol-formation process or vertigenesis, is caused, firstly, by initial seasonal overmoisturing, and, secondly, by interaction of clayey parent material with transitional solutions, containing great amount of magnesium and silica. Replacement or hydrogen by magnesium and silica, that taker place in the mineral framework, leads to transformation of minerals into montmorlllonite. Vertigenesis ts connected with domination of swelling clays, ferruginized and aluminized montmorlllonite in soils,

102 represented, to the certain degree, by magnesium and sodium varieties. Colour of vertisols varies from brown tp black and depends on two processes: ferslallltlzatlon, that causes brown colour, connected with increased content of Iron oxides, and hydromorphic process (especially paleo-), which determines dark colour, probably appearing as a result of transformation of humlc and fulvoadds to humin; and also as a result of presence of paleogleylc signs - concretions and films of iron - manganese oxides.

Annual seasonal overmolsturing of vertisols, and subsequent drying, leads to periodical swelling and shrinking and to formation of coarse-blocky structure. These soils are characterized by wide cracks, down to the depth of 1,5 meters in dry season and viscosity in humid season; high compaction of the whole soil profile; surface mulch-layer with the thickness of 5 cm, usually having more coarse texture; presence of slickensides. They have a thick soil profile with stretched diffusive bounds of transitions between genetic horizons. Alluvial-carbonate horizon lays in the lower part of the soil profile (90-120 cm). Carbonates are represented in the form of concretion or pseudomycelliu, sometimes in the form of big concretion. Hydromorphic signs can be observed all over the soil profile horizons: in A-horizon - rusty small mottles of iron oxides, in B and C horizons-also black small mottles and concretions of manganese oxides.

Content of humus in vertisols is not high and gradually decreases with depth. S-value is high and increases with the depth (30.3-40.7 mg-eq/100 g). The soil exchange complex is saturated with calcium (40-60% ) and magnesium (38-48%). Content of sodium is increasing with the depth (0.5-2.3 mg-eq/100 g) and accounts for 5-6% from S-value. The majority

103 of vertisols is characterized by leaching from upper horizons; that is proved

by high values 01 hydrolytica! acidity (to 8.9-10.0 mg-eq/100 g) and subacid reaction of soil solution up to 5.0-5.3 pH. Content of ready-soluble salts is increasing in the iower horizons. Content of sodium ion in the soil solution is

0.09-0.25 as an average, in some cases - 0.40; HCC>3-ion - 0,11-0,62, in some cases 1.00 mg-eq/100 g. Content of the soluble residue after evaporation of soil solution is 0.02-0.6% as an average. Soils are non-saline as a whole.

However, it should be mentioned, that in some soil profiles the results of analyses of abridged soil solution display increased values for the soluble residue-0.14-0.2%. Some of the chromic vertisols are characterized by unfavorable chemical com- position of soil solution, especially in lower horizons: content of HC03-ion (to 0.98-1.00) and Na+-ion (to 0.58-0.70) exceed the total amount of Ca2+ and Mg2* ions (0.20-0.46 mg-eq/100 g). These soils can be defined as potentially or deeply saline, in accordance with instruction in use (Pochvenno-meliorativnoe obosnova- nie..., 1985), as the content of water-soluble Na" and HC03* at the depth 150-200 cm exceeds the values 0.6 and 0.8 mg-eq/100 g, accordingly. They are spread widely over the territory of the "Alvero" project. The results of analyses also displayed slight Na* and HCO3* salinity of lower horizons of vertisols and some clayey varieties of brown siallitic savanna soils. Besides, most of these potentially saline soils are characterized by increased content of absorbed sodium, and therefore soils are identified as slightly or medium sodic.

These data have been also obtained by the foreign investigators. Specialists from Holland, from "Euroconsult" have also found out sodic vertisols on the left bank of the Baro river. A. Finck (1961) identified

104 vertisols with signs of slight salinization in Sudan, on the territory of Sudan Gesira, genetically bound with the Baro-Akobo plain.

Vertisols clayey texture with silt and physical clay content, increasing with depth.

Planosols are intrazonal soils and occur in the form of separate spots among brown siallitic savanna soils and vertisols. They have been formed on deluvial sediments with clay-loamy composition and are connected with flat river valleys and large gentile-sloping ravines of the flat plain.

Characteristic features of planosols are: well-defined binary profile with coarse texture in the upper part and fine in the lower part of the profile; presence of whitish exuvial A2 horizon, with leached out bases, iron ancf silty particles, presence of low-permeabie alluvial B horizon in the lower part of the soil profile with increased content of absorbed sodium and fine texture, sub- acid reaction in the upper part of the soil profile and alkaline - in the lower part, signs of overmoisturing in the lower part in form of rusty mottles. Taking into account their properties and morphology, planosols are typical for tropical conditions and resemble solods, formed in dry steppe zone of temperate latitudes.

Formation of planosols may take place during recurrent influence of weak solutions of sodium salts on non~saline soils. In this case, soil profile becomes, at first, sodic; then descending water flows wash the soil out intensively and remove products of alkaline hydrolysis. Decay of

105 alumosilicate part of so I and formation of amorphous silicor takes place under the influence of alkaline solutions to some extent.

Solod process is accompanied by distinct differentiation of soil profile. Silt and physical clay content is sharply increasing down the soil profile with evident accumulation in the middle and lower parts. The values are-in Ai- horizon 7,8% 21,4%; A2 - 7,5%, 20-9%; Bi - 17,1%; 32,5%; BC - 46,4%; 59,7% respectively. Content of sandy fraction is sharply decreasing down from 70,0 and 73,3% in Aj and A2 horizons respectively and to 40,6 and 27,6% in B and C horizons respectively. Content of silt fraction is negligible and accounts for 16,6-23,8% as an average. Content of humus is low and rapidly decreases with depth: in Ai-horizon - 1,1; in B - 0,3-0,1%. S-value is not high in the upper part (A, Bi horizons - 4,2-7,0) and is high in the lower part of the profile (BC, C horizons - 10,5-20,6 mg-eq/100 g). Among the exchangeable bases magnesium prevails in the upper part (37-43%) and calcium - (38- 47%) - in the lower part.

Content of absorbed sodium is increasing down the profile: Ai, B horizons - 0,3-1,0; BC, C horizons - 1,2-2,5 mg-eq/100 g; that accounts for 5-12% of total cations content. Soils are slightly and medium sodic, non-saline. Soil solution reaction in the upper part is slightly acid (pH 5,6-6,0), in the lower part neutral slightly-alkaline (pH 6,7-8,0).

Thus, in Baro-Akobo interfluve natural succession of red ferallitized soils of Ethiopian highlands and ferruginous soils of high foothill plain by brown siallitic savanna soils and vertisols of low and flat plain takes place. Such gradual transition of one soils to another is caused by mesorelief and parent material distribution and represents a typical soil catena. Soil cover of the Valley, besides main soil types, consists of meadow-swamp alluvial soils and lithosols and also of the fourteen soil combinations of soil types and subtypes due to the percentage of each component. On the lower taxonomic level the structure of the soil cover is determined by numerous soil complexes and associations, identified in microrelief and also by generic and specific diagnostic features. Lately, during the intensive agricultural development of the Baro-Akobo interfluve ferruginous tropical and brown siallitic Savanna lightly and medium loamy soils became more perspective in agricultural aspect. Developing of this territory is connected with mass migration of the inhabitants from North- East and Central regions of Ethiopia, that have been suffering from severe drought already for a number of years, and it begins with cutting down of xerophytic deciduous forests, savanna open woodlands and ploughing up soils. They began to construct the weir on the Akobo river for irrigating a tract with the area of 10000 hectares.

There is also no doubt, that such an intensive anthropogenic activity is destroying natural ecological balance, formed in savanna, and it can lead to unpleasant consequences. Clear felling of tropical forests and unregulated exploitation of ferruginous soils will cause intensified effect of solar radiation on the soil surface. Free iron oxides when drying may be cemented and can form impermeable crust. Irrational irrigation of potentially and deeply saline and deeply-sodic clayey varieties of vertisols and brown siallitic savanna soils of low and flat plain can make their salinization and solonetz processes more active. To avert possible negative consequences of anthropogenic activity during intensive agricultural development of the territory a complex of soil-conservation measures should be worked out.

REFERENCES

Zonn S.V. and Omar A.D Slito- i vertiflenez v pochvah umerennoi i troptcheskoi zon. J. Pochvovedenie,

1985, 12, 48-61 0n Russian)

Ivanov V.V., Lemma D., Rozanov B.G. and Sokolova T.A O sostave pochv Ephropskogo nagoria. J. Pochvovedenie, 1985, 3, 29-39. On Russian)

Kovda V.A. Pocfivennaia kartii mira 1:10000000. Akademia Nauk. GUGK. M.. 1675 (in Russian)

Pochvennaia nomenklatura na tusskom i inostrannih iazlkah (rekomendacii k malenalam X Mejdunarodnogo Kongressa pochvovedov). Knifla I. II (sostavitel Rozanov B .G ), M . 1974, 482 s.; 273 s. (in Russian)

Pochvenno-mellorativnoe obosnovanie proektov meliorativnogo slroitelstva (posobie k VSN-33-2.1.02 -85 'Pochvennie iziskama dVia meliorativnogo stro'rtelstva'). M.. 1985, 313 s. (m Russian)

Rozanov B.G., Rozanova I.M. Korreliada predstavleniy o pochvenboi katene Vostochnoi Afriki po 900- kilometrovomu profilu ot Kicumu (oz. Viktoria) do Mombasi (Indiyskiy okean). Kenia.- V kn.: Problemi sovetskogo pochvovedenia. Tr. sovetskih pochvovedov k Xli Mejdunarodnomu Kongressu pochvovedov, M., 1982, 151-158. (In Russian)

Rozanov B.G., Chliadnik P.T. ochvi raiona Gambeli v Ephiopii - Vestnik MGU, ser Pochvovedenie. M.. 1983, 4, 9-14. (in Russian)

Soil Map oftheWorld, 1;5000000, Paris, FAO/UNESCO, 1974. vol. VI

Finck A. Classification of Gesira clay soil - Sotl Sci.. 1961. 92, 4, 263-267

108 Table 1. Chemical properties of Red ferallitized soil of Ethiopian Highlands.

Absolute height is 1500 meters

Exchangeable • acidity Soil Horizon, Exchangeable according to Hydrolytical Exchangeable cations profile depth of H, according Daicukhara acidity No sampling Humus, pH to G edroilz % Ca Mg

mg-eq/1 OOg

1598 Aj 0-15 10,5 4,4 12,1 5.1 18,7 1,2 , 0,7

AB 15-35 6,4 4,3 10,5 4,3 16,2 0.7 0,5

B, 45-55 3,9 4,3 7,0 4.0 12,5 0,6 0,4

B2 70-80 2,0 4,2 4,1 3,7 10,4 t0.4 0.2

B2 120-130 1,2 4,3 3,8 4,0 10,2 0,4 0,2

BC 170-180 0,8 4.2 2,4 1.1 , 7,8 0,7 0,2

BC 210-220 1,0 4,3 2,6 3,0 7,7 0.6 0,1

C 240-250 4,2 1,2 2,5 5,8 0.5 0.2

109 Table 2. Chemical Properties of the Soils of the Baro-Akobo Interfluve.

Motto Horizon, nutrients So« depth of % Exchangeable cations. mg-eq/100 g. HydroUttc Degree of according profile sampling. PH acidity, Na Oniani, No cm mg-eQ/100g. saturation Humus. Humus. Ca Mg Na K Total % PjO,

Ferruginous tropical

2034 Ai 0-5 5.3 7.0 15,0 7.8 0.4 1.4 24,6 1.3 1.6 76,0 7 10-20 4.4 5.0 11.0 6.0 0.1 0.2 17.3 5.5 0.6 8.1 6 B, 30-40 2.0 4.6 8.5 4.0 0.1 0 2 12,8 8.2 0.8 2,9 * BC 70-80 1.0 4,7 7,2 3.8 0.1 0 2 11.3 3.5 0.9 C 100-110 0,6 4,8 5,5 3,0 0,1 0.1 8.7 3.4 1.1 - 160-170 1.2 5.0 7.8 4.5 0.1 0 2 12.8 3,3 0.8 - Brown saitatic savannas

1203 Ai 5-15 2.8 6.6 7.0 1.8 0.3 0,3 10.4 1.9 3,2 32,0 1 AB 20-30 1.4 6,5 3,2 2 2 c 0 5,7 1.6 4,7 7.0 1 B. 50-60 1.0 6.4 3.0 3,1 c 0 0.4 1.8 4 2 BC90-100 0.4 6.2 2.6 2,6 « 0 5.5 1.8 4.9 C 140-150 0.1 6,4 4.0 2.6 € 0 8.9 1,3 - 4.9 180-190 0.1 8.0 17.8 7.6 « 0.2 25,9 6.1 1.2 . Dark vertisol

1504 A, 5-15 2.9 5.8 18,0 10,8 0.5 1.0 30,3 3.6 1.7 12,8 8 AB 40-50 1.8 7,8 20.0 14.0 1.7 ■ 36,7 3,4 4,6 12,0 8

Bi 80-90 1.6 7.5 17,5 14,0 1.1 1.1 33.6 0.5 3.2 - C 100-110 0,8 7.5 22.5 13,8 2.0 U 39,5 0.3 5.1 170-180 0,5 7.8 22,7 14,7 2.3 10 J 40,7 0.1 5.6 - Planosoi

1238 A, 0-11 1.1 5.6 2.0 3.0 1.0 1.0 7.0 3.9 14.3 4,3 6 A2 11-22 0.5 5.8 1,4 1.6 0.6 \ 2 4 2 3.1 12.8 3.4 5 B, 40-50 0.3 6.0 3.0 2.5 0.3 0.6 6,4 3.1 5.3 2,6 7 BC 70-80 0.1 8.5 4.5 3.8 ^ 2 1.0 10.5 4.0 114 - 100-110 0.1 6.7 9.7 5.0 2,1 0.5 17,3 3.6 12,1 -

C 130-140 - 8.0 11.9 5.8 2.5 0.4 20.6 2.0 12,1 -

110 ECTOPARASITES OF SMALL MAMMALS IN THE CENTRAL PART OF BARO-AKOBO INTERFLUVE

Lushchekina A.A., A.A. Zemskaya, G.V. Kolonin, and N.F. Darskaya

Ectoparasites of wild mammals (ticks, mites, fleas, lice of different species) play the important role in the circulation of zoonosis causative agents in the nature and in their transmission to man and domestic animals. However there are no data on fauna, ecology particularities and epidemiological importance of ectoparasites of small mammals in the central part of Baro-Akobo interfluve and no information about the natural foci of zoonoses in the territory of this region. At the same time the foci of plague, tick-born rickettsiosis, arboviruses' etc. had been recognised in several African countries, including the countries neighbouring with Ethiopia. In connection with supposed large scale complex development of Baro-Akobo interfluve (the building of irrigation system, the enlargement of crop areas, the formation of new settlements and integration of old ones) there is the potential danger of increasing of people and domestic animals contacts with the "hidden" natural foci of diseases and of appearance of epizootic and epidemic outbreaks. For prevention of these undesirable consequences of agricultural development and detection of pathogens, the profound study of agents circulation in the wild nature, as well as the opportune elaboration of preventive measures are necessary.

At the first stage of the investigation complex, the potential circle of vectors and carriers of natural focal diseases must be established. With this purpose in February-March and in October-November 1987 the

111 reconnaissance has beer conducted to collect the ectoparasites (Gamasidae mites, Ixodidae ticks, TrombicuHdae mites and fleas) of the small mammals. The description and the analysis of species composition of collected insects, their distribution and abundance on different hosts in various biotopes are presented in this report The identification of TrombicuHdae mites has not been yet completed. These data will be published later. It should be noted that TrombicuHdae mites were founded only in October-November. The ectoparasites were collected from small mammals, having been captured on trap lines (100 traps per one line with exposition from 1 to 3 days). Three fold check of traps (at 8 o'clock in the morning, at 12-13 o'clock in the day time and at 18-19 o'clock in the evening) practically excluded incomplete count of ectoparasites, as the latter had no time to escape from captured animals. The small mammals were caught in natural stations: 1) the high-grass savanna (with burn plots, where cereals shoots had sprouted) with rare scattered trees on the flat non-drained plain, flooded during the wet season3; 2) the high-grass savanna with sparse wood-bush vegetation (on the elevated plain, unflooded during the wet season along the Gilo river near the settlem ent); and in the stations modified bv m an: crop fields (sorghum and maize), cotton fields, buildings and adjacent parts of settlements. Because of transport lack only 3 types of stations were examined in October-November (in February-March - 5).

Altogether 4850 traps/days were accomplished (2400 in Februa­ ry-March and 2450 in October-November). It was caught 480 small mammals (304 in February-March and 176 in October-November, re­ spectively, 12.5 and 7.0 specimens per 100 traps at an average) having

The maximal rainfall (about 2000 ran) was during the Deriod of. the summer southwest monsoon (June-October)

112 belonged to 5 families and 10 species (Order Rodentia - 8 species: Euxerus erythropus*, Graphiurus murinus, Tatera valida, Mus tene//uss, Mastomys erythroleucus, M. huberti6, Arvicanthis dembeensis, Lemniscomys striatus', order Insectivora - 2 species: Crocidura tuna macmillani3, C. flavescens). Moreover 2 specimens of Genetta tigrina, captured with trap were examined. From all small mammals captured the ectoparasites were collected, using the generally accepted methods (Metody izuchenia., 1964. Ten imagoes of ixodid ticks were taken from the clothes of people, having worked sometimes in savanna. The ixodid ticks were collected too from a tortoise and a snake (the species of the latter were not identified). The authors are thankful to L.A. Lavrenchenko and A.N. Milishnikov for their participation in small mammals capturing, as well as to L. N. Medvedev for help in collection of ectoparasites. We are grateful to V. M. Neronov for his reviewing of our manuscript.

The material collected is not big, however for its comparative analysis we tried to estimate the abundance of each group of ectoparasites on different hosts, in various types of biotopes (natural and modified) examined. With this purpose we calculated the abundance indexes of Gamasidae mites, ixodid ticks and fleas, otherwise their quantity on a standard count unit - 100 traps/days (Beklemisheve, 1970). In February-March 1987 the abundance index of Gamasidae mites was 9.6 in

* E . erythropus, having been iust knocked off by car, was taken on rh^ road.

5 The ectoparasites on these two, the least abundant species of small mammals, were not found, and they were net included in the table.

" For these ecological-parasitological investigations M. erythroleucus and M. huberti were not differentiated. They are presented in the article as rodents of g. Mastomys.

113 the high-grass savanna on the plain, flooded during the wet season, varying form 23 to 35.1 in modified biotopes and in high-grass savanna on elevated unflooded plain (the Gilo river bank). In October-November the abundance of Gamasidae mites in the high-grass savanna on the flooded plain increased up to 27.1 per 100 traps/days, and in the cotton fields and settlements it was considerably less (1.5 and 10.2, respectively). The catching of the small mammals in the high-grass savanna on the elevated plain as well on crop fields was not conducted during the same period. The abundance Index of the ixodid ticks was high (4.9) in February-March on the crop fields, varying from 1.6 to 0.5 in other biotopes.

The ixodid ticks were founded on the small mammals from cotton fields neither during dry, nor during wet season. In October-November this index was 8.6 in the high-grass savanna on the flooded plain and 0.4 - in the settlements. The fleas were completely absent on the small mammals caught in Figure. Distribution of ectoparasites of smalt October-November. In Feb­ mammals in different biotope types in February-March 1987. ruary-March their abundance index I • high-gnu tavbnna N lh bum plots and swu* (hoots d*m"9 the dry season) With scattered trees on the flat notvdrained plain, Doodad during the m l h m w ; on the small mammals, having been II -cotton Bald on th» plain, flooded during the wet season. III - Iwglvgrass u n n n a nWi ipana woods and bushes on the etmMd caught on the cotton fields, was plain unfeodad during the wst season along the Olio rive* bank twar l ho settlement IV - crap fteMe (sorghum and matte) on the OMO river high bank bi tie high (45 specimens per 100 high-paae Sevan n* on the elevated plain non-flooded during fca «fft

traps/days). In the other biotopes "*'*** 1 - srodtd licks 2 - Gamaafcfea nwas. 3 - flan

114 the abundance index of fleas was less high (from 15.6 in the mgn-grabb unflooded savanna to 0.3 in the localities). The distribution of all ectoparasite groups in the biotopes examined in February-March, when the investigations had been conducted most completely, is shown on the figure. The abundance indexes of different groups of the ectoparasites in the modified landscapes (mainly the crop fields existing for a long time) and the biotopes adjacent to the settlements (the high-grass savanna on the elevated unflooded plain, along the Gilo river bank not far from settlement) are higher, compared with the natural biotopes. Its probably caused by the higher hosts abundance and the better conditions in the surviving stations for the blood suckling insects, being in all stages of their development. The cotton field and the settlements, where the small mammals were caught, were formed not so late (maximum 2 years ago). So the favourable conditions for preimagoes of parasites, as well as the population of the small synanthropic mammals, had not yet been formed there.

The species of genus Mastomys, as well as Lemniscomys striatus and An/icanthis dembeensis, were the most numerous and widely distributed in the studied biotopes. These rodents were caught generally in the anthropogenic landscapes and in the high-grass savanna on the elevated plain, unflooded during the wet season, along the Gilo river bank near the settlement. They are also the main hosts of Gamasidae mites. The abundance index of mites was 12.8 on the rats of genus Mastomys-, 8.8 on L striatus; 3.2 on A. dembeensis in February-March, and 2.7, 16 and 2.7, respectively, in October-November. About the same abundance indexes of ixodid ticks (0.8; 0.5; 0.7) were observed on the rodent species mentioned above, in February-March. They were a little higher in October-November: from 0.5 on the rats of genus Mastomys to 2.6 on L. striatus. The role of A.

115 dembeensis, as a host of the different species of fleas, was significant In February-March (the abundance index 4.4). The males of the small mam­ mals were more infected by ectoparasites, than females in the region on study: e.g. 3.6 Gamasidae mites per one male, compared with 2 mites per female. Such distribution is typical for Lemniscomys striatus in the first place. It is caused perhaps by the greater mobility of the males. The analysis conducted allows us to judge, in the most general form, about the distribution of ectoparas tes of small mammals in the natural biotopes of different types, as well as about the tendency to the change of this distribution, taking into account the increasing of the anthropogenic press.

The group of Gamandae mites is the most numerous and varie^ one in our collection. Altogether 1246 Gamasidae mites, having belonged to 4 genera and 15 species, were collected and identified during our work. It was not observed any particu ar differences In the species composition of mites, collected during the dry season (February-March) and during the wet one (October-November). The identification of mites was done by Dr. A.A. Zem­ skaya, using the surveys on the Gamasidae mites of the Afrotropical region (Coffel, Retief, 1972; Strandtmann, Mitchell, 1963; Till, 1963).

I. G am asidae mites

1. Androlaelaps arvicanthis (Radford) - was found on Arvicanthis niloticus in Uganda, then in India. In Nigeria it is one of the numenJbs species parasitizing gerbils Tatera kempii. On other animals it is rare. 489, l5o' and 9N were found on Tatera valida and lcf on Arvicanthis dembeensis having been caught in the hlgh-grass savanna (with bum plots and cereal

116 shoots) with scattered trees on the flat non-drained plain flooded during the wet season.

2. Androlaelaps zulu (Berlese) - is distributed in the South Africa, Transvaal, Zuiuland and was noticed in Egypt (Keedan, 1956; 1962). It is wide distributed in Nigeria and is related with many animal species (Uranomys fox/, Dasymys incomtus, Arvicanthis niloticus etc.). We collected 24t and 2u on Lemniscomys stratus, 6t on Arvicanthis dembeensis and 4t on genus Mastomys specimens caught on the crop fields in February-March and in the high-grass savanna on the plain flooded in October-November.

3. Androlaelaps murinus (Berlese) - was described on collection from Zuiuland. The more precise description of this species was given by C.D. Radford (1939). It was noted in different places of the Afrotropical region and was found on many animal species, but its abundance on hosts was not high. In the region on study it was found 9i, on Lemniscomys striatus, 3t and lu on Tatera valida, 3t on the representative of genus Mastomys and 3t on Arvicanthis dembeensis. These mammals were caught in the high-grass savanna on the plain flooded during the wet season.

4. Androlaelaps zuluensis (Zumpt.) - was found on Aethomys namaquensis in Zuiuland. It was found in the Southeast Africa, and was on Arvicanthis niloticus in Egypt; it wasn't numerous on Tatera kempii and Rattus rattus in Nigeria. It was collected by us 6t on genus Mastomys specimens and It, IN on Arvicanthis dembeensis in crop fields and in settlements.

117 5. Androlaelaps casalis (Berlese) - widely distributed nest parasite of birds, seldom found on mammals. It was noted on Rattus rattus and Xerus . * ' ? mauris In different parts of the Afrotropical region. We found 19 on one specimen genus Mastomys in one settlement In February-March.

6. Androlaelaps irtermedius (Okereke) - was described, having been collected on Tatera kempii from West Nigeria. We collected 26v, 2cf and 3N on Tatera valida caught in the high-grass savanna on the plain flooded In October-November.

7. Androlaelaps desymydis (Radford) - is distributed in South Africa as parasite of Tatera alfa and Mystromys albicaudatus. We founc it on Tatera valida (19, IN ) caught on the sorghum field in February-March.

8. Echinolaelaps giganteus (Berlese) - is widely distributed in the Afrotropical region. It was noted in Liberia, Nigeria, Uganda, Kenya, Zululand, Zimbabwe. It was found on many rodent species. A number of authors (Coffel, Retief, 1972; Zumpt, 1961 et al.) reported a significant morphological variation of this species. In the region on study it was the most numerous and widely distributed species: 119 and lc f were found on Arvicanthis dembeensis, 4599 and 2cf on Lemniscomys striatus and 29 on Crocidura flavescens.

9. Echinolaelaps muricola (TrSgardh) - was described from the mountain Kilimanjaro region, then was noted on many animal species in the dKftrent regions of Africa (Hirst, 1923; 1925). F. Zumpt (1950; 1961) reported the wide distribution of this species all over the Afrotropical region.

118 V

It is the second species on its abundance in our collection, being related mainly with the rodents of g. Mastomys (1999, 2cf, IN collected) and less related with Lemniscomys striatus (739, 2o', 2N). Several specimens only were found on Arvicanthis dembeensis (289, lcO, Tatera valida (89), Graphiurus murinus (19). This species was observed in all biotopes.

10. Echinoiaeiaps ugandanus (Hirst) - was found in Uganda. We found lcf on one specimen of g. Mastomys captured in settlement in November.

11. Laelaps nigeriensis (Keegan) - was noted in Nigeria on Mus musculoides and Crocidura sp.. T. A. Okereke (1966) reported that these mites were found in a small amount on Mus musculoides, Lophuromys sikapusi and Desymys incontus in West Nigeria. We collected 669, and IN on Arvicanthis dembeensis; 119 on rodents genus M astom ys; and 69 on Lemniscomys striatus. The animals were captured in almost all types of examined biotopes except cotton field.

12. Laelaps ibadanensis (Okereke) - was described from West Nigeria. In the studied area it was one of the numerous parasite species of genus Mastomys rodents (1139, 30o' and 13N). It parasitized too on Lemniscomys striatus (79, IN), Arvicanthis dembeensis (59, lc f) and Tatera valida (19, lcr). This species was found in all types of biotopes, but general amount of mites was arranged for settlements.

13. Laelaps langei (Okereke) - the small species similar to Laelaps nigeriensis. It was described from West Nigeria, been related with many

119 rodents spedes e.g. L’ranomys foxi, Lophuromys sikapusi, Arvicanthis niloticus, several specimens only were found on Lemniscomys striatus, Tatera kempii and others. We collected 8? and IN on Lemniscomys striatus, 109 and lcf on Arvicanthis dembeensis and 69 on genus Mastomys specimens. These mammals were caught mainly on crop fields In February-March.

14. Laelaps sp. - this species has not yet been Identified. Probably It's the new form for the sdence and further Investigations are needed for its description. We found 39 of this mite on Tatera valida in the high-grass savanna on the plain flooded In October-November.

15. Omythonyssus sp. - two protonymphs, not identified, were found on the same gerbll, from which mites Laelaps sp. had been collected.

The fauna of Gamasidae mites in studied area is peculiar. The free-living forms of mites were not presented In our collection. The facultative parasites of Laelapidae family were only found. The obligate parasites were not numerous. Only 2 protonymphs Omythonyssus sp. (Omythonyssldae family) were found. Predominant mites on their abundance were spedes of g. Echinolaelaps, Echinolaelaps giganteus was 35,3% of all mites collected. It was found on 5 spedes of small mammals and was most abundant on Lemniscomys striatus. Echinolaelaps muricola (21,6%) was found on 9 species of animals and was usual for rats of genus Mastomys. On Lemniscomys striatus It was slightly less frequent. Androlae­ laps arvicanthis related mainly with Tatera valida was found to be predominant spedes of g. Androlaelaps (4,8%). The mites Androlaelaps murinus (2,2% of collection) were found on animals of 5 species In single in­

120 stances. These Gamasidae mites belong to the afrotropical species and are : • • * ' distributed in the West-African as well in the East-Afrtcan subregions. The mites Androlaelaps zulu (2.4% of collection) were found mainly on Lemnis­ comys striatus. Mites A. zulu and A. zuluensis are distributed Southward from Sahara more widely, than all species mentioned above; they are known also from Egypt. The mites Laelaps ibadanensis (11.9% of collection) art more frequent (particularly on rodents of genus Mastomys) than other species of genus Laelaps. Laelaps nigeriensis (5 .7 % ) was found on 5 species of small mammals (particularly on rodents of genus Mastom ys) than other species of genus Laelaps. Laelaps nigeriensis (5.7%) was found on 5 species of small mammals (particularly frequently on Arvicanthis dembeensis.) Lae­ laps langei found on 4 animal species was even more rare (1.7%). These species (L. ibadanensis, L. nigeriensis, L. /angei) and Androlaelaps intermedius were known recently from Nigeria only. One representative of holarctic fauna - Androlaelaps casalis was found in the studied region. This is a wide-spread species. Mainly related with birds, although it wasn't rare on rodents too.

Their are many publications in the world literature about many species of mites, ensuring infective agent circulation in the natural foci of diseases (Zemskaya, 1973). It can be explained by the fact, that the Gamasidae mites are the most mass ectoparasites, related with the different animal groups, many of them being the carriers of infective agents of diseases,- Moreover almost all species of parasitic mites are capable to^the blood­ sucking. This contributes to infective agent safety In all seasons of the year. The Gamasidae mites have mainly epizootic importance, as more part of them being related with small mammals and birds. Only some species of mites can have epidemiological importance (Zemskaya, 1973). The Gamasidae mites can b« the vectors of endemic murine typhus, vesicular rickettslosls, Q fever, plague, erizinelold, toxoplasmosis. AH these diseases are characteristic for African continent (Rukovodstvo Po Zoonozam, 1983). It's not excluded that some of them, being purposefully investigated, can be found in Ethiopia, including the Baro-Akobo interfluve.

II. Ixodldae ticks.

The ixodid ticks are the second group of ectoparasites (on Its abundance and variety cf forms) of small mammals In the central part of Baro-Akobo interfluve. It was collected 269 specimens of the Ixodid ticks, having belonged to 7 species of 3 genera. It wasn't observed any significant differences In species composition of ticks collected in February-March and in October-November. When identifying the ticks (by Dr. G. V. Kolonin), the number of surveys on this group were used (Morel, 1976; Morel, Rodhaln, 1973; Pegram et al., 198:.).

1. Haemaphysalis adculifer (Warb.) - inhabits East and South Africa. Adult ticks parasite generally antelopes, and Immature stages - the small and medium-sized mammals (Hoogstraal, Kammah, 1972). We found IN and 2L on Arvicanthis dembeensis, captured in the high-grass savanna on the flooded plain.

2. Haemaphysalis howyi (Nutt, et Warb.) - specific parasite of ground squirrel Euxerus erythropus, whose area stretches from Senegal to the western part of Ethiopia. 4cf, 19, 2N were collected from Euxerus erythropus, picked up on the road in February. 3. Haemaphysalis spinu/osa (Neum.) - it is wide-spread In Africa Southward from Sahara. Imagoes parasitize the small and medium-sized carnivores, more frequently the viverrlds; nymphs and larvae the small mammals of different species (Hoogstraal, 1964; Hussein, Mustafa, 1983). In the studied area it was collected 6cf, 89 on Genetta tigrina, 2N, 25L on rodents of genus Mastomys, by one nymph on Tatera valida and Arvicanthis dembeensis, caught mainly in modified landscapes.

4. Hyalomma truncatum (Koch) - its area spreads all over Africa southward from Sahara except the zone of tropical rain forests. Adult ticks parasite the large wild and domestic mammals, Immature stages - the small mammals (Kolonin, 1983). In February 49 were gathered by us from a man in the high-grass savanna on the flooded plain.

5. Rhipicephalus simus (Koch) - the species characterised by the wide ecological plasticity; inhabits in various landscapes of East and South Africa. The circle of its hosts is also very vast (Kolonin, 1984). In our case they are Genetta tigrina ( lt f ) and Lemniscomys striatus - 19 R. sim us. The animals were caught on the sorghum field and near it.

6. Rhipicephalus senegalensis (Koch) - the species similar to Rhipicephalus simus replacing it in West and Central Africa. 39 of this species were taken from a man In the high-grass savanna on the .flooded plain.

7. Rhipicephalus sp. - these ticks have not yet been identified. They are numerous In our collections: 65N, 6L on Tatera valida; 35N, 15L on

123 Arvicanthis dembeensis 47N, 19L on Lemniscomys striatus IN, 7L on genus Mastomys, lcf and 29 were taken from a man. These ticks were spread in all types of biotopes.

Except the ticks, being taken from the small mammals and a man, lcf Ambtyomma nuttaliii (E>omtz) was found on tortoise and l2cf, 1? and 4N Aponomma latum on a snake (not identified).

All species found In the studied area are wide-spread and usual for the different regions of African continents, induding Ethiopia. The not identified ticks of genus Rhipicephalus are 56% of.all our collection. This genus is wide-spread on the studied area, and the representatives of it parasite on the small mammals of dominant spedes. Haemaphysalis spinulosa - the next species on Its abundance (15% of collection), parasitizing the rats of genus Mastomys. The rest spedes are about in the same proportion of total sum of collected ticks. The absence of the immature ticks of g. Hyalomma and Amblyomma In our collections (the numerous parasites of agricultural animals) can be explained by the fact, that domestic cattle practically doesn't graze on the studied area, and the abundance of wild ungulates, the primary hosts of these parasites, was reduced In recent years.

The ixodid ticks take the most active part in preservation and prevalence of infective agents of the different natural focal zoonoses. They have mainly the epidemiological importance. Being the mass parasites, they are related with the large drde of animals, the carriers of pathogens, and can transmit pathogens not only from animal to animal, but man to man too. On the African continent the ixodid ticks are the main vectors of Crimean-

124 -Congo hemorragic fever, Marcel and Q-fever and of other zoonoses (Ruko­ vodstvo Po zoonozam, 1983).

III. Fleas

The fleas have the less various species composition and abundance, compared with the groups of mites and ticks described above. However their potential role in the natural foci of zoonoses is great enough. During the work it was collected 192 fleas specimens of 3 species, belonging to 2 genera. The fleas were identified by dr. N. F. Darskaya, when using the survey oh ecology and distribution of fleas (Lewis, 1972) and the number of ■' other publications. As it was said above, the fleas on the animals were found during the dry season only (February-March). In principle it coincides with observations made by J.E.C.Flux (1972), who had established the dear expressed seasonal abundance dynamics of these ectoparasites 'In the different regions of Kenya. We consider, that additional investigations are needed for revealing and study of ecological particularities of fleas and other ectoparasites in the southeastern part of Ethiopia.

I. Xenopsylla cheopis (Rothschild) - it has the almost cosmopolitan distribution and was found on all continent except the Antarctic (Lewis, 1972). The wide spreading of this species can be explained b.V 5 parasitizing the small mammals, related with man. It was found 63?, 41cf on Arvrcanthis dembeensis', 209, 120* on the rats of genus Mastomys', 49, lcr on Crocidura flavescens; by on female on Tatera valida and Lemniscomys striatus. The animals, been infested by fleas Xenopsylla cheopis, Inhabited

125 in the settlements (dwellings and food stores) and on the crop and cotton fields.

2. Xenopsylla nubica (Rothschild) - the species, spread almost all over the Africa. It Is known as parasite of gerblls and Jerboas (Lewis, 1972). We revolted 259 and 15cr from rodents of g. Mastomys caught as in settlements, as well on the cotton field. In the high-grass savanna on the elevated unflooded plain these fleas were found on Tatera valida (49, 3cf) and by one female on Arvicanthis dembeensis and Lemniscomys striatus.

3. Ctenocephalides felis fells (Bouche) - the widely spread species, related with carnivores. Only one female was revolted from Genetta tigrina, caught near the sorghum field.

All described fleas are wide-spread and usual on the African continent. The most numerous species Xenopsylla cheopis (74% of collection) parasites the large circle of hosts (5 species). In several countries this flea Is the vector of plague. It must be noted that rodents of genus Mastomys, on which this fleas was most frequently found, were shown more than once as carriers of plague In Africa. Moreover the fleas of some other species take part In transmission of pathogens of endemic murine typhus, Marcel fever and so on (Rukovodstvo Po zoonozam, 1983; Tlflov, 1960).

It Is known that nature transformations, being accompanied by the anthropogenic landscapes creation, Influence the spreading character of Infections diseases and zoonoses first of all. In our times the process of evolution of several diseases pathogens Is sharply accelerated and Is

126 measured literally by decades (Baroyan, 1968). The transformation of landscapes can lead to the fading of fod and even to the disappearance of them, as well as to their activization, to the appearance of another fod, to the adaptation of co-members of parasitic triad to the new conditions (Rukovodstvo Po Zoonozam, 1983). The conducting of reclamation works for Irrigation of arid areas can contribute to the considerable enrichment of species composition of animal population. The channels banks serve as ecological courses, being used by rodents (natural reservoirs of Infections) for their settling. The irrigation contribute to animation of transmission of the arboviral infections (mainly the fevers). The raising of underground water JeveJ and the Incorrect using of Irrigated lands contribute to the great reproduction of some vectors of transmissible Infections. The extending of crop fields from one side can result to the appearance of mass reproduction outbreaks of rodents, from another side to limit the abundance of these rodents, and hence, of their ectoparasites, limiting the existence possibilities of fod of plague, tularemla^vQ-fever and other natural focal diseases (Ruko­ vodstvo Po Zoonozam, 1983). However the partial lands development leads to the special redistribution of rodents, to considerable Increasing of theirs population density on the unploughed plots and on the edges of crop areas. In Its turn It can contribute to the maintaining and even increasing of pathogens circulation In the natural fod. The network extending of roads and foot paths, owing to Integration of old settlements and creation of new ones on the developed territory, increases possibilities of the small mammals migrations and danger of Infections bringing and spreading In the.regions, where they were not earlier. The edges of roads and paths are the olaoes of ticks concentration.

127 To Identify the true role and extent of participation of ectoparasites and their hosts - the snail mammals In the circulation of pathogens in the natural foci of Infections, as well as to study the possible changes of epidemiological situation in the region of irrigation system building, in the central part of the Baro-Akobo lnterfluve,*1t is necessary to perform during different seasons the detail ecological, parasitological and serological Investigations in the nacural and modified biotopes, and try in the nearest future to Identify the circle of pathogens, danger for man and domestic animals, circulating in these cenosises.

REFERENCES j -

Baroyan O.V. Itogi poluvekovoy oorbys Infectiyami v SSSR , M.. 1968, 302 s.

Beklemishev V.N. BlocenotogtavesWe osnovt sravnttetnoy perezitotogii., M „ Nauka, 197Q. 502 s. (In Russian),

Coffal G.M.,Reti«f l_A. The laelaps muricola complex in the Ethiopian region; Description of a new species and a new subspecies (Acarina. Mesastigmata) J.Med.Ent. 1972,3.4.

Flux J.EC ,?ie ason al and regional abundance of fleas on hares in Kenya J.East Africa Nat. Hist. Soc. Nat. Mus',*1972.135,1-8

Hirst 8. On some new or little-known species of Acarl. Proc. Zool. Soc. London, 1923, 917-1000

Hirst 8. Descriptions of new Acad, mainly parasitic on rodents. Proc. Zool. Soc. London, 1925, 49-69

Hoogstraal H. Notes on african HeemaphysaHs ticks. VI. H. Spmuiosa Neumann and Is relation to biological and nomen ciatorial problems in the H. ieacttgroup of Africa and Asia (bcodoidea, Ixodidae). J. Pares!, 1964, 5Q, 8, 786-791

Hoogstraal H., Kammah ICM. Notes on afrtcan Haemaphysaite lick*. X.H. (Kaiseriana) adcudfer Warburton and H. (K) rugosa Santos Dias, the african representatives of the spMgera subgroup (bcodoidea. ixodidae). J. Paras*. 1972, §§, 5,960 -978

128 Hussein H., Mustafa B. Haemaphysalls (Rhipistoma) spinulosa Neumann, 1906: description of immature stages, adult structural variations, and notes on biology (lxodoidea: bcodidae). J.Paraaft. 1983, §9, 2, 403-412, 417-424

Keegan H.L. Ectoparasitic Laelaptid and Dermanyssid mites of Egypt, Kenya, arid the Suoan, rrinwtiy based on the Namru Collections, 194S-1953. J. Egypt.J?ubi. Hith. Ass., 1956, 3 1 ,199-272

Keegan H.L. A new ectoparasitic laelaptid mite from Africa. J. Parasitol., 1962,4 3 .4 . 621-622

• ' , J * I • / - ’’ :•« Kolonin 6.V. Mirovoye rasprostranenle Iksodovih kleschey. Rod I Hyalomma, Aponomma, Ambtyomma., M.. 1983, 121 s.

Lewis R.E. Notes on the Geographical Distribution and Host preference In the order Siphonaptara. J.Med.Ent., 1972, g, 6, 511-570.

Metodi izucheniya prirodnlh ochagov boiezney cheloveka (Red. P A . Petrischeva, N .G. Otsufiev), M.. 1964, 307 s.

Morel P.C. Etude sur les tlques d'Ethlople (acariens, ixodides). Inst. d'Bev. Med. Vet. Pays Trop. Malsons Alfort, France, 1976, 326 p.

Morel P.C., Rodhain F. Contribution a la connaissance des tiques du sud de I’Ethlopie. Premiere parte- Bull. Soc. Path. Exot., 1973, g§, 725-732

Okereke T.A . Fauna i ekologlya krovososuschih gamazovlh klechey Zapadnoy Nlgerli, Kand. dis., M.. 1966, 24 s.

Pegram RA., Hoogstraal H., Wassel H.Y. Ticks (Acarina: lxodoidea) of Ethiopia. I. Distribution, ecology and host relationships of species infesting livestock. Bull. Entom. Res.-, 1981,21, 3, 339-359

Radford C.D. Noles on some new species of paras/tic mftes. Parasftoiogy, Cambrige, 1939, 30, 427-440

Rukovodstvo Po zoonozam. M„ Medidna, 1983, 320 s.

Strandtmann R.W., Mitchell C.J. The Jaelaptine mites of the Echinolaelaps complex from the Southwest pacific area. Pacific Insects, 1963, §, 3, 541-576

Trflov V.E. Znachenie bioh v rasprostranenii boleznye. Tr.n.-i. protivochumnogo in-ta Kavkaza i Zakavkaziya, 1960, vip .4,15-34.

129 Till W.M. Ethiopian mites or the genus Androlaelaps Bert. (Afrtcana. Mesosttgmais). Bull. Brit. Mus. (Nat. hist.), Zool., 1963, 10, 1,1-104

Zemskaya A A ParasitichesJue gamazovie Weschi i ih medtdnsXo ye znachente. M . Medicine, 1973.168s.

Zumpt F. Notes on some parasitic mites Some remarks on the family Laelaptidae (Sensu Vrtzthum 1943) with description of three new species from African rodents Parasitology, 1950, _4Q. 3-4. 298-303

Zumpt F. The arthropod parasites of vertebrates in Africa South of the Sahara (Ethiopian Region). V.l. (Chelicerata) Putt. S. Afr. Inst. Med Res.. 1961, N.L (Vol. XI)

130 LONGHONR BEETLES (COLEOPTERA, CERAMBYCIDAE) COLLECTIONS IN SOUTH-WESTERN ETHIOPIA

M urzin S.V.

Twenty three species of beetles referred to Cerambycidae were collected in the Baro-Akobo interfluve (administrative district Illubabor, South-Western Ethiopia). With our imperfect knowledge of Ethiopian fauna, we consider It interesting to present the list of longhorn beetles collected. The author acknowledges L.N. Medvedev and L.B. Rybalov who have provided the material to be processed.

THE SUBFAMILY PRIONINAE

Tribe Eragatfnl

Genus Mallodon Serville, 1832

1. Mallodon downesi Hope, 1843

Occurrence: Africa southward of the Sahara, Madagascar.

Ethiopia: 30 Km westward of Abobo, 10-21. III. 1986 (L.B. Rybalov), using a light source 1 female; In the same place. 2. II. 1987 (L.B. Rybalov), using a light source, 1 female: Gambela, 29.X.1967 (L.B. Rybalov), using a light source, 2 males.

Tribe Macrctomlnl

Genus Macrotoma Serville, 1832

2. Macrotoma natala Thomson, 1860

Occurrence: from SAR to Ethiopia.

131 Ethiopia: 30 km westward of Abo bo, 15.XI.1966 (L.N. Medvedev), using a light source; 2 males; in the same place. 10-21 XU.1686 (L.B. Rybalov), using a tight source. 1 female; in the same place. 2.XI.1987. using a light source, 1 female: Gambeia IX.1985, 1 male.

Tribe Acanthophorlnl

Genus Ttthovs Thomson, 1964

3. Tithoes confinis Castelnau, 1840

Occurrence: Africa southward of the Sahara.

Ethiopia: Gambeia. IX. 1985, 1 female.

THE SUBFAMILY CERAMBYCINAE

Tribe Xystrocerin!

Genus Xystrocera Servilie, 1834

4. Xystrocera nigrita Servllle, 1834

Occurrence; from Senegal and Cot d'lvoir to Mozambique. First reference for Ethiopia.

Ethiopia: 30 km westward of Abobo, 19.XI.1966 (L.N. Medvedev), using a light source, 1 male, 2 females; in the same place, 29.IX.1986 (L.B. Rybalov). using a light source. 1 male.

5. Xystrocera dispar Fahraeus, 1872

Occurrence: Africa southward of the Sahara.

Ethiopia: 30 km westward of Abobo, 19.Xl.1986 (L.N. Medvedev). Using a light source, 1 male; In the same place, 25.XI.1686 (L N . Medvedev) using a light source. 1 male.

Tribe Methlini

Genus Coptoeme Aurovillius, 1904

6. Coptoeme variabilis Hintz, 1919

Occurrence: Zaire. First reference for Ethiopia.

Ethiopia: 30 km westward of Abobo, 19-25.XI.1986 (L.N. Medvedev), using a light source, 1 male, 1 female; in the same place, 4.XI.1987 (L B . Rybalov), using a light source, 1 male. 1 female. Genus Brunoeme Viliers, 1972 7. Brunoeme rufo/imbata Vflllers, 1972

Occurrence: described from Ethiopia.

Ethiopia: 30 km westward of Abobo, 19-25.XI.1986 (L.N. Medvedev), using a light source, 2 females, in the same place, 10-21 XII.1988 (L.B. Rybalov), using a light source, 2 females

Genu* Hypoeschrus Thomson, 1864

8. Hypoeschrus abyssinicus Jordan, 1894 (ssp. dalloni Peyerim)

Occurrence: from Ethiopia and Chad to Tanzania. Subspecies H.a.dalloni described from Chad

Ethiopia: 30 km westward of Abobo, 19-25.X1.19S6 (L.N. Medvedev), using a light source, 1 male.

9. Hypoeschrus ugandensis Lepesma, Breuning, 1955

Occurrence: Kenya, Uganda. First reference for Ethiopia.

Ethiopia: 30 km westward of Abobo, 25.XI.1988 (L.N. Medvedev), using a dght source, 2 males, 3 females; in the same place, 10-21 .XII.1988 (L.B. Rybalov), using a iiflhtsource, 1 female.

Tribe Cerambycinl Genus Plocaedorus Thomson, 1860

10. Plocaederus cyanipertnis Thomson, 1960

Occurrence: from Gambia to Angola and Zaire. First reference fo r Ethiopia.

Ethiopia: 30 km westward of Abobo, 24.XI.1986 (L.N. Medvedev), using a light source, 1 male, 1 female.

11. Plocaederus sp

Ethiopia: 30 km westward of Abobo, 26.XII.1986 (L.B. Rybalov), using a light source, 1 m «e.

Tribe Hesperophanfnl

Genus Cerasphorus Serville, 1834

12. Cerasphorus hirticomis Serville, 1834

Occurrence: from Guinea to Zaire and Angola. First reference for Ethiopia.

Ethiopia: 30 km westward of Abobo, 19-25.XI.1988 (L.N. Medvedev), using a light source, 2 males, 3 females; In the seme place, 7.XI.1987 (L.B. Rybalov), using a light source, 1 male, 1 female.

133 THE SUBFAMILY LA Ml INAE

Tribe Apomtcynlnl

Genus Ampomecyna Latraille, 1829

13. Ampomecyna trifdsdata Quedenfeldt, 1883

Occurrence: from Angola to Somali and Guinea

Ethiopia. 30 km westward of Abobo, 10-21 XII. 1986 (L B Rybalov), using a light source. 1 species

14. Apomecyna longepennis Thomson, 1858

Occurrence: from Guinea to Sudan and Zaire First reference for Ethiopia.

Ethiopia: settlement Damslie. 18 km eastward of Abobo. 22.XI.1086 ( I N. Medvedev), 1 species.

Tribe Ptoroplllnl

Genus Nlphona MuJsant, '839

15. Niphona appendicufata Gerst., 1871

Occurrence: tropical Africa

Ethiopia: 30 km westward of Abobo, 25.XI.1986 (I N . Medvedev) using a light source, 1 species.

Tribe Ceroploslnl

Genus Ceroplesls Serville 1835

18. Croplesis militaris Gerstaecker, 1855

Occurrence: from SAR to Kongo and Somalia

Ethiopia: 30 km westward of Abobo, 15-25.XI.1986 (L N . Medvedev), using a light source. 2 males: in the same place. 29.XI. 1986 (LB . Rybalov), using a light source. 1 male

Genus Analapt^a Gist., 1848

19. Analeptes trifasdata Fabricius, 1775

Occurrence: tropical Africa.

Ethiopia: Gambela, 29.X.1987 (LB . Rybalov) using a light source 1 male Tribe C ro s s o tin i

G en us C ro s s o tu s Serville, 1835

20. Crossotus plumicornis Serville, 1835

Occurrence: from Senegal to Somali.

Ethiopia: 30 km westward of Abobo, 25.X I.1986 (LN . Medvedev) using a light source, 1 species.

Tribe P h ry n e tin i

G en us P h ry n e ta Cast., 1840

21. Phryneta spinator Fabricius, 1792

Occurrence: tropical Africa.

Ethiopia: Gambela, 29.X .1987 (L.B. Rybalov), using a light source, 1 female.

Tribe R h o d o p in i

G en us S o p h ro n ic a Blanch., 1845

22. Sophronica aureovittata Aurivillius, 1907

Occurrence: Cameroun. First leference for Ethiopia.

Ethiopia: Gambela, 23.XI.1986 (L.N. Medvedev), 1 species; 25 km westward of Abobo, 23.X.1987(L.B. Rybalov), using a light source, 1 species.

Trib e Phytoeciini

G en us N u p s e rh a Thomson, 1860

23. Nupserha basalis basipennis Fairmaire, 1887

Occurrence: the species occurs from Senegal to Angola and Uganda. First reference for Ethiopia.

Ethiopia: 30 km westward of Abobo, 15-29.XI.1986 (L.N. Medvedev), 5 males, 2 females.

135 ON THE RHOPALOCERA (LEPIDOPTERA) FAUNA OF SOUTH-WESTERN ETHIOPIA

Gorbunov O.G., and V.K. Tuzov

The entomofauna of accessible Ethiopian uplands has been studied rather completely (Carpenter, 1935; Rougeout, 1977; Ungemach, 1932), while the Rhopalocera Lepidoptera of south- western Ethiopia is still completely unexplored. The present publication is based on the collections at the administrative district of Illubabor (southwestern Ethiopia) carried out by L.N. Medvedev and L.B. Rybalov who are acknowledged for the provision of materials to be processed.

The system and nomenclature of butterflies are given from the monograph by D'Abrera (1980).

THE FAMILY PAPILIONIDAE

G en us P a p ilio Linnaeua, 1758

1. PapHio dardanus Brown, 1776

Occurrence: forest areas of the tropical Afnca Has a variety of geographical fonins Our species refer to the subspecies a n tinorii Oberthur.

Ethiopia: 1 female. 1 male, Gambela, XI. 1987 (L.B Rybalov) in the same place. X11987 (L.B. Rybalov), 4 males. 1 female; 20 km eastward of Abobo. 5-12.XII 1986 (L.N. edvedev), 3 males.

2. Papilio nireus Linnaeus, 1758

Occurrence: Africa southward of the Sahara. In Ethiopia, Uganda, northern Kenya - subspecies pseudonireus Felder.

136 Ethiopia: Gambeia, X I.1987 (L.B. Rybalov), 9 males, 1 female; 20 km eastward of Abobo, 5-13.XII.1986 (L.N. Medvedev), 33 males; 30 km westward of Abobo, 24.X.1987 (L.B. Rybalov), 1 male, 1 female.

3. Pap/l/o demodocus Esper, 1798

Occurrence; Africa southward of the Sahara.

Ethiopia; Gambeia, XI. 1987 (L.B. Rybalov), 8 males, 1 female; 20 km eastward of Abobo, 4-11.XII.1986 (L.N. Medvedev), 3 males; in the same place, 22.X I.1987 (L.B. Rybalov), 2 males. 1 female.

4. Papilio echerioides Trimen, 1868

Occurrence; Eastern Africa. The available species refer to the subspecies oscari Rothschild widespread at the Ethiopian uplands westward of the Rift valley.

Ethiopia; Gambefa, X I.1967 (L.B. Rybalov), 1 mate; 20 km eastward of Abobo, 10 XII.1966 (L.N. Medvedev), 1 male; in the same place, 7.X.1987 (L.B Rybalov), 1 male.

G enus G ra p h iu m Scopolic, 1777

5. Graphium ango/anus Goeze, 1779

Occurrence: tropical Africa. In Ethiopia - the subspecies baronis Ungemach

Ethiopia: Gambeia, 29.X.1987 (L.B Rybalov), 1 male, in the same place, X I.1987 (L.B Rybalov), 1 female, 20 km eastward of Abobo. 11 .XII. 1986 (L.N Medvedev). 1 male; in the same place. 22 X1.1987 (L.B Rybalov), 2 males; 30 km westward of Abobo. XI 1986 (L.N. Medvedev) 1 male.

6 . Graphium leonidas Fabricius, 1793

Occurrence, common over the whole continent southward of the Sahara.

Ethiopia: Gambeia, XI 1987 (L.B. Rybalov), 1 female; 20 km eastward of Abobo, 5-8.XII.1986 (L.N. Medvedev), 3 males, in the same place, 22.XI.1987 (L.B. Rybalov), 1 female.

7. Graphium antheus Cramer, 1779

Occurrence: forest areas of the continental Africa southward of the Sahara.

Ethiopia Gambeia, XI. 1987 (L.B. Rybalov), 1 male; 20 km eastward of Abobo. 8-11.XII. 1986 (L.N. Medvedev), 4 males; in the same place, 22.XI.1987 (L.B. Rybalov), 1 male.

137 THE FAMILY PIER/DAE

G en us Catopsilla Hubner 1819

8. Catopsilia fJorella Fabricius, 1775

Occurrence: the whole Afrotropical region

Ethiopia: 20 km eastward of Abobo, 22 X11987 (L B Rybalov). 1 male 1 female. Addis-Ababa. 25 XI 1987 (L.B. Rybalov). 1 female

G en us E u re m a Hubner, 1819

9. Eurema hecabe Linnaeus, 1758

Occurrence savannas and orests of the whole Afnca. Indo-Malayan and Australian regions In Africa - the subspecies solifera Butler

Ethiopia: 20 km eastward of Abobo. 8.XII.1986 (L N Medvedev). 1 male. 30 km westward of Abobo 17.X.1987 (L.B Rybalov,. 1 male.

10. Eurema brigitta Stool, 1780

Occurrence: the whole Afrotropical region

Ethiopia: Gambela. XI11986 (L.N. Medvedev), 1 male 1 female, in the same place X11987 (L B Rybalov), 1 female; 20 km eastward of Abobo. 3-5 XI11986 (L.N. Medvedev). 2 males, 1 female. 30 km westward of Abobo. 17.X.1987 (L.B Rybalov), 1 male.

11. Eurema senegalensis Boisduval, 1836

Occurrence: tropical Africa. First reference for Ethiopia

Ethiopia: 20 km eastward of Abobo, 22.XI 1986 (L.N Medvedev) 2 males: in lha same place 10.XII.1986 (L.N Medvedev). 1 male.

12. Eurema desjardinisi Boisduval, 1833

Occurrence: nominate subspecies occur In Madagascar, the whole continental Africa southward of the Sahara is inhabited by the subspecies regutoris Butler

Ethiopia: 20 km eastward of Abobo. 5.XII.1986 (L N Medvedev) 1 male. 1 female

Genua Nepheron/a Butler, 1870

13. Nepheronia thalassina Boisduval, 1836

138 Occurrence: the whole tropica) Amca. The subspecies sinalata Suffert is widespread in the east of the region.

Ethiopia: Gambela, 11.XI.1987 (L.B. Rybalov), 1 male; 20 Km eastward of Abobo, 5.XII.1986 (L.N. Medvedev), 1 male, 1 female, in the same place 7.X.1987 (L.B. Rybalov), 2 males.

Genus Eronla Hubner, 1823

14. Eronia leda Boisduval, 1847

Occurrence: south-eastern part of the continent from Ethiopia to the South African Republic (SAR).

Ethiopia: 20 Km eastward of Abobo, 5-10.XII.1986 (L.N. Medvedev). 2 males.

Genus C o lo tis Hubner, 1819

15. Coiotis protomedia Klug, 1829

Occurrence: arid low mountain areas (up to 1500 m above sea level) from Sudan in the east to Nigeria in the west.

Ethiopia: 30 Km westward of Abobo, 17.X.1987 (L.B. Rybalov), 1 female.

16. Colotis danae Fabricius, 1775

Occurrence: common in the Afrotropicai and Indo-Malayan regions. The subspecies eupompe Klug is widespread in arid low mountain areas of Africa southward of the Sahara and northward of the equator.

Ethiopia: Gambela, XI.1987 {L.B. Rybalov), 1 male.

17. Colotis eucharis Fabricius, 1775

Occurrence: like the previous species. The subspecies evame Klug occurs in dry forests and savannas from Senegal to Somali.

Ethiopia: Gambela, XI.1987 (L.B. Rybalov), 1 male; 20 Km eastward of Abobo, 22.XI.1986 (L.N. Medvedev), 2 males; 30 km westward of Abobo, 17.X.1987 (L.B. Rybalov). 3 males. 1 female.

18. Colotis evippe Linnaeus, 1758

Occurrence: the whole tropical Africa. The subspecies exole Reiche occurs in southern Sudan. Ethiopia and Somali.

Ethiopia: 20 Km eastward of Abobo, 5.XII.1986 (L.N Medvedev), 1 male.

139 19. Colotis evagore Klug, 1829

Occurrence; the nomlnat subspecies inhabits Arabia the subspecies anfjgone Boisduval is noted in arid landscapes over the whole Africa southward of the Sahara

Ethiopia: Gambeia, XI.1987 (L.B Rybalov). 1 male 20 Km eastward of Abobo. 5.XII 1986 (L N Medvedev). 1 female; 30 km westward of Abobo. 7-17 X 1987 (L B Rybalov). 2 males 3 females

20. Belenois creona Cramer, 1776

Occurrence, from Senegal to western Ethiopia. Madagascar

Ethiopia. 30 km westward of Abobo. 2 XII 1986 (L.N Medvedev) 1 male 1 lemaie

21. Belenois subeida Felder et Felder, 1865

Occurrence the whole tropical Africa. The subspecies h/emalis Ungemach inhabits Ethiopia

Ethiopia: 30 km westward of Abobo. 17 X 1987 (L B Rybalov) i female

22. Belenois calypso Drury, 1773

Occurrence: the whole tropical Africa. The subspecies haifo Ungemach is noted in southern Ethiopia and south-eastern Sudan

Ethiopia: Gambeia, XI 1987 (L B Rybalov). 1 male; 20 km eastward of Abobo, 22.XI-3.XII.1986 (L.N Medvedev), 6 males. 1 female, in the same place 6 XI 1987 (L B Rybalov). 1 female. 30 km westward of Abobo, 0.XI1987 (L B Rybalov), 1 male. 1 female

23. Belenois solilucis Butler, 1874

Occurrence tropical forests from northern Angola to south-western Ethiopia where the subspecies /oven/ Aurivilllus occurs

Ethiopia: 20 km eastward of Abobo. 22.XI-5 Xtl 1986 (L N. Medvedev), 5 males

24. Belenois gidica Godard, 1819

Occurrence, the whole continenlal Afrotropical region.

Ethiopia: Gambeia, 29.XI.1987 (L.B Rybalov). 3 males. 3 females, 20 km eastward of Abobo, 3-5.XII.1986 (L.N Medvedev). 3 males. 30 km westward of Abobo. 17-28 X 1987 (L.B Rybalov), 2 males, 4 females. Addis-Ababa. 25.XI.1987 (L 0 Rybalov), 1 male. 2 females

Genus P o n tla Fabricius, 1807 25. Pontia daplidica, Linnaeus, 1758

Occurrence widespread species in Paleractica In Africa is known from high mountain Ethiopia (the subspecies aethiopa Jannis et Verity)

Ethiopia: Addis-Ababa. X 1986 (L N Medvedev) 1 male, in the same place, 25 XI 1987 (L.B Rybalov), 1 male.

G en us D ix e ia Talbot, 1932 26. Dixeia pigea Boisduval, 1836

Occurrence tropical forests from Ethiopia in the north, Cameroon in the west and SAR in the south

Ethiopia 20 km eastward of Abobo 5-10 XII 1986 (L N Medvedev) 2 males. 1 female

27. Dixeia orbona Geyer, 1837

Occurrence the whole tropical Africa The subspecies vidua Butler inhabits the eastern part of the areal.

Ethiopia 20 km eastward ot Abobo 3 XI) 1986 (L N Medvedev). 3 males

G en us M y lo th ris Hubner, 1819 29. Mylothris chlons Fabricius, 1775

Occurrence the whole tropical Africa The subspecies agathina Cramer is noted in the eastern pari of the continent

Ethiopia: Gambela, 29 XI 1987 (L B Rybalov) 1 male 2 females

G en us L e p to s ia Hubner, 1818 20. Leptosia nupta Butler, 1873

Occurrence: Africa southward of the Sahara The subspecies pseudonuptilla Bernardi inhabits Ethiopia.

Ethiopia. 20 km eastward of Abobo, 5 XII 1986 (L.B Rybalov). 2 males. 2 females 30 km westward of Abobo. 2.XII.1986 (L.N Medvedev) 1 male

THE FAMILY ACRAEIDAE

G en us A c ra e a Fabricius, 1807 30. Acrae insignis Distant, 1880

141 Occurrence eastern tropical Africa from Ethiopia to Mozambique.

Ethiopia: Gambela, XI.1987 (L B . Rybalov). 1 mate, 1 tamale 20 km eastward of Abobo, 4-8 XI11986 (Li*. Medvedev), 5 males, 2 females

31. Acraea ehcedon Linnaeus, 1758

Occurrence Africa southward of the Sahara. Madagascar. V •»» - 1 Ethiopia: Gambela, 5.XII.1986 (L.N. Medvedev). 1 mate; In the same place. XU. 1987 (L.B Rybalov). 3 . mates, f female; 20 km eastward of Abobo, 4-8.XII.1908 (L N . Medvedev). 2 males 1 female. 30 km westward of Abobo. 2_X)t 1996 (L B . Rybalov), 1 mate, In the same place. I7-24.X.1987 (L B Rybalov). 9 males. 3 females; Addte-Ababa, 25.X1.1987 (L .a Rybalov), 1 mate. 1 female

32. Acraea caldarena Hewltson, 1877

Occurrence: south-eastern part of the African continent from Ethiopia in the north Angola in the west and SAR in the south. Firs! reference for Ethiopia.

Ethiopia. 20 km eastward ot Abobo, 22X1.1987 (L.B. Rybatov). 1 female.

33. Acraea acerata Hevwltson, 1874

Occurrence; river valleys of Africa southward of the Sahara and northward of Ihe Zambezi and Kunene rivers.

Ethiopia: 20 km eastward of Abobo. 22.XI.1987 (L.B. Rybalov). 2 males; 30 km westward of Abobo, 2.XII.1987 (L N . Medvedev), 1 female. Y 1 # 34. Acraea natalica Boisduval, 1847

Occurrence: central part of the continent from Senegal in the west to Kenya and Ethiopia in the east, produces a number of subspecies forms. In Ethiopia - the subspecies abadime Ribbe

Ethiopia: Gambela, 28 X 1 987 (L.B. Rybalov), 1 male; in the same place. XI.1987 (L.B Rybalov), 3 females; 20 km eastward of Abobo. 3-5.XII.1986 (L.B. Rybalov). 3 males; in the same place, 22.XI.1987 (L.B Rybalov). .1 mate; Addis-Ababa. 25.XI.1987 (L.B Rybalov). 1 male

35. Acraea terpsicole Linnaeus, 1758

Occurrence: western part of Indo-Malayan region, Central and Southern Afrtca. The subspecies neobute Ooublday occurs from Cameroon to Kenya

Ethiopia: Gambela, 29 X1 987 (L.B. Rybalov). 1 male

142 THE FAMILY DANAIDAE

Genus Danaus Kluk, 1802 36. Danaus chrysippus Linnaeus, 1758

Occurrence: Southern Paleoarctica, Indo-Malayan and Australian regions; the whole Africa -*he subspecies aegyptius Schreber.

Ethiopia: Gambeia, XII.1986 (L.N. Medvedev), 1 male; in the same place, 29.XI.1987 (L.B. Rybalov), 8 males; 20 km eastward of Abobo, 8-13.XII.1988 (L.N. Medvedev), 8 males; in the same place. 22.XI.1987 (L.B. Rybalov), 2 males.

37. Danaus petiverana Doublday, 1847

Occurrence: forest areas from Ethiopia to South Rhodesia.

Ethiopia: Gambeia. X I.1987 (L.B. Rybalov). 1 male; 20 Km eastward of Abobo, 22.XI.1986, 22.XI.1987 (L.B. Rybalov), 2 males, 1 female; in the same place, 8 XII.1988 (L.N. Medvedev), 1 male; 30 km westward of Abobo, 15.X.1987 (L.B. Rybalov), 2 males.

38. Amauris niavius Linnaeus, 1758

Occurrence: tropical Africa. The subspecies aethiops Rotschild et Jorden occurs in southern Ethiopia, Southern Sudan and Northern Uganda.

Ethiopia: Gambeia, X I.1987 (L.B. Rybalov), 1 male; 20 km eastward of Abobo, 22.XI.1986, 22.XI.1987 (L.B. Rybalov), 2 males, 1 female; in the same place, 8.XII.1986 (L.N. Medvedev), 1 male; 30 km westward of Abobo, 15.X.1987 (L.B. Rybalov), 2 males.

Genus Amauris Hubner, 1816 38. Amauris niavius Linnaeus, 1758

Occurrence: tropical Africa. The subspecies aethiops Rotschild et Jorden occurs in southern Ethiopia, Southern Sudan and Northern Uganda.

Ethiopia: Gambeia, XI.1987 (L.B. Rybalov), 1 male.

THE FAMILY SATYRIDAE

Genus Melanftls Fabricius, 1807 39. Melanitis leda Linnaeus, 1758

143 Occurrence: Indo-Malayan. Australian and Afrotropical regions The subspecies helena Westwood occurs in Africa.

Ethiopia: Gambela, XI. 1987 1_B. Rybalov). 1 male, 1 female

40. Melanitis lybia Distant, 1882

Occurrence: tropical forest areas of the Eastern Africa from Mozambique to Ethiopia

Ethiopia: 30 km westward of Abobo, 17X1987 (L.B. Rybalov), 1 male

Genus S/cyc//* Kirby, 1871

41. Bicydis vulgaris Butler, 1868

Occurrence, secondary forests from Gambia and Angola to Uganda and Tanzania First reference for Ethiopia

Ethiopia: 20 km eastward of *bobo, 5-10.XII.1986 (L.N Medvedev). 4 males 30 kin westward of Abobo. 24.X. 1987 (L.B Rybalov), 1 male.

42. Bicydis sophrosyne Plotz, 1880

Occurrence: tropical forests from Cameroon through northern Zaire to Uganda and western Kenya. First reference for Ethiopia

Ethiopia: 20 km eastward of Abobo. 4-20.XII.1986 (L.N Medvedev). 5 males: 30 km westward of Abobo, 24.X.1987 (L.B. Rybalov), 1 male.

43. Bicydis trilophus Rebel, 1914

Occurrence: Southern, Central and Western Zaire. Gabon First reference for Ethiopia.

Ethiopia: 20 km eastward of Abobo, 5.XII.1986 (L.N. Medvedev) 1 male

44. Bicydis technatis Hewitson, 1877

Occurrence: forest areas from Cameroon to Zaire and Angola First reference for Ethiopia

Ethiopia: 20 km eastward of Abobo, 10.XI11986 (L.N Medvedev). 2 males.

THE FAMILY NYMPHALIDAE

Genus Phalanta Horsfield, 1828

45. Phalanta phalantha Drury, 1773

144 Occurrence: tropics of the Old World, in Africa is represented by sethiopica Rothschild et Jordan.

Ethiopia: 20 km eastward of Abobo, 5-11 .XII.1986 (L.N. Medvedev), 3 males; 30 km westward of Abobo, 21 X. 1987 (L.B. Rybalov), 1 male.

Genus Hypollmnas Hubner, 1819

46. Hypolimnas misippus Linnaeus, 1764

Occurrence: subtropica and tropics of the Old World.

Ethiopia: Gambeia, 28.X.1987 (L.B. Rybalov), 1 male.

47. Hypolimnas dubius Palisot de Beauvois, 1806

Occurrence: forests of the tropical Africa. The species available slightly differ from the nominate species.

Ethiopia: Gambeia, XI.1987 (L.B. Rybalov), 1 female; 20 km eastward of Abobo, 5.XII.1986 (L.N. Medvedev), 1 male; in the same place, 7.X.1987, 22.XI.1987 (L.B. Rybalov), 3 males, 1 female; 30 km westward of Abobo, 12X.1987 (L.B. Rybalov), 2 males.

Genus Salamis Boisduval, 1833

48. Salamis temora Felder, 1867

Occurrence: from Eastern Nigeria and Angola to Western Kenya and Ethiopia.

Ethiopia: Gambeia, XI.1987 (L.B. Rybalov), 1 female.

Ganus Juncmla Hubner, 1819

49. Junonia orithya Linnaeus, 1758

Occurrence: Indo-Malayan, Australian and Afrotropical region. In the African continent represented by madagasc.arienis Guenee.

Ethiopia: Gambeia, XII. 1986 and XI.1987 (L.B. Rybalov), 2 males; Addis-Ababa, X.1987 (L.B. Rybalov), 2 males.

50. Junonia oenone Linnaeus, 1758

Occurrence; the whole Afrotropical region.

Ethiopia: Gambeia, 29.XI.1987 (L.B. Rybalov), 2 males; 30 km westward of Abobo, 17.X.-6.XJ.1987 (L.B. Rybalov), 5 males, 1 female.

145 51. Junonia hierta Fabricius, 1798

Occurrence: subtropics and tropics of the Old World In Africa the subspecies cebrene Trimen.

Ethiopia: 30 km westward of Abobo. 21.X.1987 (L.B Rybalov). 1 male

52. Junonia chorimena Guerin, 1844

Occurrence: Senegal. Sudan. Uganda. Western Kenya and Ethiopia

Ethiopia: G*nbela, 29.XI.1087 (L.B. Rybalov). 2 males; 20 km eastward of Abobo. 3-11 XII. 1986 (L.N Medvedev). 5 males; 30 km westward of Abobo, 7.X. 28.X, 6 X1.1087 (L.B Rybalov). 5 males. 1 female

53. Junonia terea Drury, 1770

Occurrence: Africa southward of the Sahara The subspecies fum ata Rothschild et Jordan occurs in Ethiopia.

Ethiopia: 20 km eastward of Abobo, 10-13.XII.19M (L.N. Me#vedev). 3 males

54. Junonia antilope Feisthamel, 1850

Occurrence: subarid savannas southward of the Sahara

Ethiopia. 20 eastward ol Abobo, 10.Xti.1966 (L N . Medved«v).1 mate, in the same place 22 XI 1987 (L.B. Rybalov), 1 male: 30 km westward of Abobo. 24 X.1987 (L 6 Rybalov). 3 males. 1 female

0 * n u « Byblia Hubner, 1819

55. Byblia Hithyia Drury, 1770

Occurrence, open arid areas of Africa. Arabia and India

Ethiopia. Gambela. XI.1987 (L.B. Rybalov), 2 males: 20 km eastward of Abobo. 22.XI.1986 (L.N Medvedev). 11 males, 1 female.

56. Byblia anvatar Boisduval, 1833

Occurrence: tropical Afnca, in the south-western pad of the continent - the subspecies acheloia Wattengren.

Ethiopia: 20 km eastward of Abobo. 11 .XII. 1986 (L.N Medvedev). 2 males: in the same place. 22.XI.1987 (L.B. Rybalov), 1 male.

57. Byblia sp

146 Ethiopia: Gambela, XI.1987 (L.B. Rybalov), 1 female; 20 km eastward of Abobo, 3-11.XII. 1986 (L.N. Medvedev). 3 males

The above species are similar to BybliB anvatara but have a number of differences in wing coloration

Gsnus N eptis Fabricius, 1807

58. Neptis nemetes Hewitson, 1868

Occurrence: forest areas of Senegal and Angola to Uganda and western Kenya. First reference for Ethiopia.

Ethiopia: Gambela, XI.1987 (L.B. Rybalov), 1 male, 1 female: 20 km eastward of Abobo, 22.XI and 5.XII.1986 (L.N. Medvedev), 2 males; in the same place, 7 X.1987 (L.B. Rybalov), 1 female; 30 km westward of Abobo, 7.26.X.19&7 (L.B, Rybalov), 1 male, 1 female 59. Neptis kiriakoffi Overlaet, 1955

Occurrence: forest areas of Africa southward of the Sahara.

Ethiopia: Gambela. XI.1987 (L.B Rybalov), 1 female; 30 km westward of Abobo, 24,X.1987 (L.B Rybalov), 1 mate.

60. Neptis melicerta Drury, 1773

Occurrence: secondary forests from Senegal in the west to Ethiopia in the east and southward of Angola and Mozambique.

Ethiopia: 20 km eastward of Abobo. 22.XI. 1987 (L.B. Rybalov), 1 female; in the same place. 8.XII.1986 (L.N. Medvedev), 2 males

Genus Euphaodra Hubner, 1819

61. Euphaedra neumanni Rothschild, 1902

Occurrence: South-Western Ethiopia and Southern Sudan

Ethiopia: Gambela. XI.1987 (L.B. Rybalov), 1 male

G«nus H aw anum lda Hubner, 1819

62. Hamanumida duaedalus Fabricius, 1775

Occurrence: semidesert areas southward of the Sahara and northward of the equator.

147 Ethiopia: Gambeia, XI. 1987 (L B. Rybalov). 1 male: 20 km eastward of Abobo. 5-8 XII 1986 (I N Medvedev). 3 males, 2 females; in the same place. 22 X11987 (L B Rybalov) 2 males. 1 female 30 km westward of Abobo, 2.XII.1986 (L.N. Medvedev) 1 female

Genus A te ric a Boisduval, 1833

63. Aterica galene Brown, 1776

Occurrence: the whole tropical Africa In Ethiopia the subspeaes inctsa Rothschild et Jordan is noted

Ethiopia: Gambeia, XI.1987 (L.B. Rybalov), 1 male; 20 km eastward of Abobo, 4 XII.1986 (L N Medvedev). 3 males, 2 femiues: in the same place. 7.X 1987 (L B . Rybalov). i female

G enus Pseudacraoa Westwood, 1850

64. Pseudacraea lucretia Cramer, 1775

Occurrence: Africa southward of the Sahara. Madagascar In Ethiopia ihe subspeaes wa/erisensis Sharpe is noted.

Ethiopia: Gambeia, XI.1987 (L.B Rybalov), 2 males 20 km eastward of Abobo. 8-11 XI11986 (L N Medvedev), 3 mates, 30 km westward of Abobo. 7 X 1967 (L.B Rybalov) 1 male

Genus C h a ra x e s Ochschenheimer, 1816

65. Charaxes achamensis Feldr, 1867

Occurrence: Africa southward of the Sahara In Kenya, westward of Ihe Rift Valley. Uganda Ethiopia and Sudan the subspecies m onticola Joicey et Talbot is widespread

Ethiopia: Gambeia, XI.1987 (L.B. Rybalov), 1 male: 20 km eastward of Abobo. 5-13 XII 1986 (L.N Medvedev). 4 males.

66. Charaxes candiopa Godart, 1823

Occurrence: Africa southward of the Sahara

Ethiopia: 20 km eastward of Abobo, 8.XII.1986 (L.N Medvedev) 1 male; Addis-Ababa, 25 XI 1987 (L.B Rybalov), 1 femaie

67. Charaxes viola Butler, 1966

Occurrence: Africa southward of the Sahara. In Western Zaire. Cameroon, North-Western Kenya. South-Eastern Sudan and South-Western Ethiopia - the subspecies picta van Somerent et Jackson.

148 Ethiopia 20 Km eastward of Abobo, 22.XI. and 11.XII.1986 (L.N. Medvedev), 3 males.

Genus Vanessa Fabricius, 1807

68. Vanessa cardiu Linnaeus, 1758

Occurrence: throughout the world, except the Neotropical region.

Ethiopia. Gambela, 29.X. 1987 (L B. Rybalov), 2 males, 2 females; 20 km eastward of Abobo, 3.XII 1986 (L.N. Medvedev), 1 male.

THE FAMILY LIBYTHEIDAE

Genus Libythea Fabricius, 1807

69. Libythea labdaca Westwood, 1851

Occurrence; forest areas from Guinea to Ethiopia.

Ethiopia: 20 km eastward of Abobo. 3-5.XII. 1986 (L.N. Medvedev), 11 males.

THE FAMILY LYCAENIDAE

G en us P e n tila W e stw o o d . 1851

70. Pentila pauli Staudinger, 1888

Occurrence; Africa southward of the Sahara.

Ethiopia. 20 km eastward of Abobo. 22.XI. 1986 (L.N. Medvedev), 1 male; .in the same place. 4.XII. 1986 (L.N. Medvedev). 5 males.

G en us Lachnocnema Trimen, 1887

71. Lachnocnema bibulus Fabricius,. 1793

Occurrence; the whole continental Africa southward of the Sahara.

Ethiopia: 20 km eastward of Abobo, 22 X I.1986 (L.N. Medvedev) 1 male.

G en us A n th e n e D ou b le d a y

72. Anthene kersteni Gerstaecker, 1871

Occurrence: forest areas of Eastern Africa from Mozambique to Ethiopia.

149 Ethiopia: 20 km eastward of Abobo, 3-8.XII.1986 (L B . Rybalov), 5 males.

The above species somewhat differ from the typical ones by a darker coloration of the upper wing side.

73. Anthene rothschildi Aurivillius, 1922

Occurrence, endemic of Ethiopia.

Ethiopia. 30 km westward of Abobo, 2.XU.1986 (L.B. Rybalov), 1 mate

G en us L e p to te s S cudd er,

74. Leptotes pirithous Linnaeus, 1767

Occurrence, south of Paleoarctica, Indo-Matyan. Australian and Atrotropical regions.

Ethiopia 20 km eastward of Abobo. 3-8.Xtl.1986 (L.B Rybalov). 1 male; 30 km westward of Abobo, 2.XII.1987 (L B. Rybalov), 5 males

76. Leptotes pulehra Murray, 1874

Occurrence: the whole Africa

Ethiopia: Gambela. 29.XI.1987 (L.B Rybalov). 1 female

G en us C a s ta liu s Hubner, 1819

77. Castalius kaffana Talbot, 1935

Occurrence: South-Western Ethiopia

Ethiopia 30 km westward of Abobo, 6.XI.1987 (L B Rybalov), 1 male.

G en us T a ru c u s Moore, 1881 76. Tarucus theophrastus Fabricius, 1793

Occurrence: arid areas from Senegal in the west to Arabia in the east.

Ethiopia 30 km westward of Abobo. 6.XI.1987 (L B Rybalov), 1 male.

79. Tarucus ungemachi Stempffer, 1944

Occurrence arid areas from Senegal to Northern Kenya

Ethiopia 30 km westward of Abobo. 6 XI 1987 (L B Rybalov), 3 males. 1 female

80. Tarucus rosacea Austant, 1885

150. Occurrence: arid areas of the Mediterranean Sea, Africa southward to Senegal, Chad, Sudan and Kenya.

Ethiopia: 30 km westward of Abobo, 6.XI.1987 (L.B. Rybalov), 1 male, 1 female.

Genus Z/zu/a Chapman, 1910

81. Zizua) hyJax Fabricius, 1775

Occurrence: Indo-Malayan, Australian and Afrotropical regions.

Ethiopia: 20 km eastward of Abobo, 3.XU.1986 (L B . Rybalov), 1 female.

Genus Azanus Moore, 1881

82. Azanus ubaldus Stoll, 1782

Occurrence: forest areas from Guinea, Uganda and Ethiopia in the north of Zaire and Angola in the south.

Ethiopia: 20 km eastward of Abobo, 8.XII.1986 (LN . Medvedev) 1 male.

83. Azanus isis Drury, 1773

Occurrence: arid areas of Western, Southern and Eastern Africa.

Ethiopia: 30 km westward of Abobo, 14.X.1987 (L.B. Rybalov), 2 males.

Genus Euchrysop s B utler, 1900

84. Euchrysops malathana Boisduval, 1833

Occurrence: arid areas over the whole Africa.

Ethiopia: 30 km westward of Abobo, 2.X1I.1986 (L.N. Medvedev) 1 male; in the same place, 17-24 X1987 (L.B. Rybalov), 13 males, 3 females

85. Euchrysops osiris Hopffer, 1855

Occurrence: arid areas over the whole Africa.

Ethiopia: 20 km eastward of Abobo. 5.XII.1986 (LN . Medvedev), 1 male.

Genus Petr&laea Toxopeus, 1929

86. Petrelaea sichela WaMengren, 1857

Occurrence: African savannas southward of the Sahara. Ethiopia: 30 Km westward of Abobo. 2.XH.1986 (L.N. Medvedev), 1 male; in the same place. 14-17.X.1987 (L.B. Rybalov), 8 mates.

Genus Z/zeer/a Chapman, 1910

87. Zizeeria knysna Trimen, 1862

Occurrence: continental Africa.

Ethiopia. 30 km westward of Abobo. 2.XI.1987 (L.B. Rybalov). 1 male

Thus, the butterflies collected refer to 87 spedes, 41 genera and 8 families, of which 7 species (6.9% ) are listed for Ethiopia for the first time.

In terms of chorology the majority of the material studied (40 species, 45.1% ) are widespread in the Afrotroptcai (Ethiopian) kingdom. The second quantitative complex is presented by the species whose areals do not exceed the bounds of the central part of the continent limited by approximately 13°N and 13°S.

The species typical for the tropics of the Old World and the ones occurred only in the eastern part of Africa make up two equal groups (9 species or 10.5% each).

The areals of 4 species (4.7%) encompass the eastern part of Africa and the western part of Indo-Malayan region, and the areals of 2 species (2.3%) - Africa and South-Western Palearctlca.

The distribution of 3 species (3 .5% ) is reduced to the Ethiopian regions, which allows to distinguish them as endemics of the Ethiopian uplands.

152 And finally, 1 species, namely V. cardui, occur throughout the world, except the Neotropical region. The areal of Byblia sp (No. 57 in the list) Is ambiguous due to the absence of specific definition.

The overwhelming majority of the species studied are statially associated with savannas, and only a small number of species (about 11%) to tropical forests and river flood-lands.

REFERENCES

Carpenter G.D.H. The Rhopalocera of Abyssinia. A faunistic Study. Trans. Roy. Ent. Soc. London, 1935,83, 313-440.

D’Abrera B. Butterflies of the World. Vol.2, Butterflies of the afrotropical region, 1980, 593 p.

Rougeout P.-C. Missions entomologiques en Enthiopie. 1973-1975, fasc. 1. Mem. Mus. Nat. Hist, nat., ser. A, Zoologie, 1977, 105,150 p.

Ungemach H. Contribution a I'etude des Lepidopteres d'Abyssinie, 1re partie, Rhopaloceres. Mem. Soc. Sci. nat. Maroc, 1932, 32,122 p

153 NEW LARVAE OF LEAF BEETLES (COLEOPTERA, CHRYSOMEUDAE) FROM SOTH-WEST ETHIOPIA

Zaitsev Yu.M.

Leaf beetles and their larvae take a special place among insects-phytophages in Ethiopia. They are present in every phytocenosis and, to different extent, are harmful for plants (particularly dangerous are their larvae). At present, the principal nucleus of fauna of leaf beetles in South-West Ethiopia has been found, but the larvae of most leaf beetles there are still unknown.

The paper provides morphological description o the larvae of 6 species collected by L.N. Medvedev in the interfluve of Baro-Akobo during the dry season of 1986. Taking this opportunity, I express my sincere gratitude to hlm.for his kind presentation of his material and the definition of the species.

Mesoplatys cincta 01

The larva is of the 2nd age. The body top is dark grayish-brown, the thorax bottom is light yellow, the bottom of the abdomen is dirty-gray; the head is black, the pronotum is dark brown; the setae are black and long, getting thinner towards the apex; they are easy to break down and to leave after breaking only some short remains or pores. The thorax has two and the abdomen has seven pairs of dermal glands which open up Dy their oval orifices. The head is rounded; the vertex Is smooth, with long setae in its front part and along the sides (Fig. 1,1). The epicranial suture is long and reaches the middle of the head; the frontal sutures are setting apart at ?;n obtuse angle and then become slightly curved; they do not reach the base of the antennae; the forehead is broad, with 10 long setae along the front edge. The clypeus is transverse, of light colour; it is only its basal part which is sclerotized into a narrow strip with a row of 6 shortened setae. The labrum (Fig. 1,2) is sclerotized; it is narrow, with sharp basal angles and rounded sides, there is a narrow and deep notch in the middle and two thick and shortened marginal setae on each side of the notch. The disc has 2 pores and 6 setae on its surface; 4 setae of the main row are long and 2 setae of the top row are thin; they are strongly shortened and hard to see; they are situated near the front edge. The setae are of 3 joints; the first joint is transverse, the second is weakly elongated, its apix has a long and narrow 3d joint, as well as a coniform sensing papilla (Fig. 1,3). The ocellae are small and convex. The mandibles are triangularly elongated and have 4 adminiculae (Fig. 1,4); the mandibular palps are of 3 joints, the labial ones are of 2 joints. The sclerites of the pronotum are smooth, slightly transverse, separated from one another by a narrow light-colour strip with a row of long setae along the edges; the epipleural sclerite of the pronotum is small, it has one unimportant setae; this sclerite is hard to distinguish and closely joins the lateral edge of the pronotum sclerite (Fig. 1,5). The tergites of the thorax and abdomen are scleritized, convex, brown; because of the dense micro-sculpture of the integuments, they are hard to distinguish. The mesodorsum and scutellum have two rows sof sclerites; the pretergal sclerites have one setae, the posttergal ones have two or three setae (Fig. 1,5). The wing sclerites are strongly convexed, with 5-6 setae, the inward sides of the sclerites are with foramens of dermal glands; the external posttergal sclerites closely adjoin the wing ones. The abdomen tergites (from the 1st to the 6th) reveal one posttergal row of sclerites (the pretergal row of sclerites is reduced); the pre- and posttregal sclerites merge

155 together, they are strongly convexed, inwardly with formens of dermal glands; the eplpleural scleites look like narrow coniform protrusions; the apix has 3-4 long setae (Fig. 1,6). On 7-9* tergltes of the abdomen the sclerites merge Into an unpaired plate; the 9th segment is coniform and narrow, with a weak plunger. The sderites of the thorax and abdomen stemltes are developed (Fig. 1,7) but on the abdomen they are hard to distinguish because of the dense microsculpture of the body Integuments. The latter look like oval-elongated grains, the microsculpture is denser on the dorsal side of the body. The spiracles are small, poorly distinguished. The legs are long, they are darker externally, the tibia-tarsus is long, the ungia are without denses and with a small chelonim (Fig. 1,8). The body Is 6 mm long, the head capsule Is 1.3 mm wide.

The material; Ethiopia, 30 km east of settlement Abobo; 18.11.1986; (LN. Medvedev), 3 larvae and beetles on shrub vegetation.

The genus Mesoplatys Baly is a typical representative of the African fauna. It includes 3 species, one of them is found on the Madagascar Island and the two others are spread in Africa. So far, sdentists knew the larvae of M. ochroptera from Mozambique (Chen, 1934). The larvae of this genus openly Inhabit leaves of fodder plants, they have well-developed dermal glands. Based on the latter, this genus was induded In the tribe Phaedonini. When the larvae were morpho-ecologically analyzed, their features were found to be phylogenetically dose to the genera Gastrophysa and Phaedon. The genus Mesoplatys differs from the latter by having long and black bristles on the top of the body, 4 bristles on the epipleural sderites and one row of tergltes on the abdomen segments.

156 v-fs?

Fig. I. Structural details of Mesoplatys cincta 1 - head, 2- fabmro, 3 - antenna, 4 - mandible, 5 - pronotum and mesonotum, 6 - 2"° abdoment tergite, 7 - 2nd abdomen stemite, 8 - tibiotarsus.

157 Fig. R.$tructural details of CasskHnae

1 - general v>ew o( Laccoptara corrugate; 2 - lateral process of Asptdomorpha schoenheni; 3 - general vie* of Aspttiomorpha apicaJis-. 4 - general view of Cassida scuteHaris; 5 - lateral process of Asptdotnorpha schoenheril; fl - a p « of caudal case in Laccoptera corrugata

158 1 - labrum of Laccoptera corrugate, 2 - la brum of Aspldomorpha apkxllr, 3 - labrum of Aspktomorpha schoenhenf, 4 -labrum of Atpidomorpha anata; 5 - labrum of Castlda scutellarir, 0 - mandible of Aspkhmorpha schoenhert, 7 - mandible of Aspktomorpha areata; 8 - mandible of Aspidomcrpha apjcalls.

159 Laccoptera comigata Shlb.

The body Is oval-elongated (Fig. 11,1), light-brown, with rare short setae having splne-llke thecas; the mlcrosclupture of body integuments looks like small thick rugas and small spines yielding oval spots on the body or sidelong narrow strips. The lateral processes are thin and tapering towards the apix; they are dark brown, especially on the thorax; the secondary branches are spine-like and of different length, they are situated on all sides of the process; the lateral processes and secondary branches have needle-shaped thecas on their apixes. The head Is light brown, the vertex on Its front and the sides has rare small setae; the fronts has long setae which are rounded or club-shaped at the aplx. The labrum (Fig. 111,1) is strongly sclerotized, strongly arched in the base; the flanks are rounded, the anterior borders s with a shallow rectangular notch the bottom of which has 6 small setae; on each side from the notch there are 3 marginal setae pressed down to the labrum margin. There are 4 pores on the disc, 4 dlscal setae In the main row, they are long and make up a regular row, the 2 dlscal setae of the apical row are long and occur at the labrum margin. The pronotum Is transverse, with two ligh-brown oval spots; It Is surrounded by small setae; between the spots there Is a longitudinal field formed by thick light setae with elongated club-shaped thecas. The anteromarginal lateral processes have all one common base; the Internal processes are slightly curved inwardly; the lateral and the posterior ones are equal. The anterior lateral processes of the meso and metathorax occur already In the base and are half as long as the posterior ones. The lateral processes of the 1st abdoment segment equal half of the segment width; on each side there are 4-5 secondary branches. The lateral apophyses of the abdomen from the 1* to the 5* are getting smaller towards the back; the 6* is longer than the 5th; the 7th and the 8th are twice as long as the 6th.

160 The meso- and metodorsum and the abdoment segments are divided in two toruli, each of them has an irregular row of small seate; the thorax has 3 pairs of sidelong strips; there are oval spots on the abdomen, they form longitudinal strips. The caudal setaes are strongly sclerotized, they are narrowed in the base and are setting apart further on; they are double-sided curved, getting gradually thinner towards the aplx. The caudal case Is composed of exuvia, but at the aplx there is a peculiar fan of thred-like excrements (Fig. 11,6). The spiracles look like short conical tubules surrounded by narrow chitinous rings; the spiracles of the thorax are larger than others; the daws are densless. The body Is up to 10 mm long; the head capsule is 1.0 mm wide.

The material: Ethiopia, settlement Dam Sait, 20 km south of settlement Abobo; 6.12.1986 (L.N. Medvedev); a large series of larvae and beetles were taken from the leaves of Inomoea.

Aspidomorpha Spicalis Klug,

The body is oval-elongated (Fig. 11,3), light-yellow; the setae can be well distinguished only on the pronotum; the microsculpture of body integuments is not Indicative. The lateral processes are cone-shaped thinned towards the aplx, on each side they have 5-6 thin and upright secondary branches which, likewise at the aplx of the lateral processes, have long styloid thecas at the end. The labrum (Fig. 111,2) is slightly transverse, light-yellow, the anterior margin Is In wardly obliquely cut and concave: It has an oval median notch the bottom of which reveals 6 short setae; on each side from the notch there are 3 marginal setae (the 2 Internal ones are thickened). The 4 discal setae of the main rown lie obliquely; the 2 setae of the apical row are short and occur near the anterior margin. The mandibles are llqht In colour, slightly triangular, with

t e i 3 sharp denses (Fig. 111,8). The pronotum Is with two ring-shaped spots between whfch there Is a field of thick interwined setae. The anteriormarginal lateral processes are dark, they have a common base; the external ones are upright, the interna; ones are curved, the lateral and spiracle processes are equal. The anterior and posterior lateral processes of the meso - and metothorax are equal, but the metaprocesses are thicker In the base than the anterior onfs. The ateral process of the 1st abdomen segment is longer than one half of the segment width. The lateral processes of the 1st to 4th segments of the abdomen get gradually shorter towards the back; the 5th is obviously longer than the 4th; the 6** and the 8th are equal and are both longer than the 5**1; the 7th Is evidently longer than the previous ones. The tergites of the thorax and abdomen have Indistinct transverse folds and rare llgh-colour setae. The lateral processes are covered with thick spines which are dark brown on the prothorax and lighter on other segments. The caudal setas are slightly sclerotized, narrow In the base; they are connate, getting more widely set apart and gradually thinning towards the case is only of exuvla. The caudal setaes of the larva of the first age are long, thinner towards the apix, with thick upright spines; on the interior there are 4 short branches, on the exterior there are 10 secondary branches; the aplx has needle-shaped thecas on the end. The spiracles look like conical tubules, they are larger on the thorax than on the other segments; the spiracles of the 1** abdomen segment are dark brown, the others are light. The claws are thin, crescent-shaped, densless. The body Is 8mm long, the head capsule is 0.8 mm wide.

The material: Ethiopia, 30 km east of settlement abobo; 1.12.1986 (L.N. Medvedev), 1 larva and beetles on the leaves of impomoea.

162 Aspidomorpha schoenherri Boh.

The description is based on the exuvlum of the larva of the last age. The lateral processes are conical, In their basal part they have small spines and are gradually getting thinner towards the apix (Fig. 11,2). The secondary branches are thin, upright and spine-like, they occur on all sides; the lateral processes and secondary branches have needle-like thecas at the end. The microsculpture of body Integuments looks like thick shrincles and dull spines, the body setae are small, with club-like thecas. The head Is light brown, the vertex has thick small spines along the sides and especially near the ocella. The frons has rare spines and setae, the latter are rounded at the apix. The labrum (Fig. 111,3) is slightly transverse, weakly convex in the base, the flanks are rounded, the anterior margin is slightly concave and has a deep tetragonal median notch; the latter has 6 small setae on the bottom, one elongated bristle on the flanks, 3 marginal setae on each side from the notch; the internal setae are thickened and widened at the apix, the two lateral ones are finepointed. There are 4 pores on the disc; 4 discal setae of the main row are short, sharp and form a regular row; 2 discal setae of the apical row are away from the front margin and are by 1/3 shorter than the setae of the main row. The mandibles are triangular, with 6 dull denses and a sharp internal edge; there are 2 setae and 2 pores on the flank (Fig. 111,6). The internal and external anteromarginal lateral processes lie on a common base; the Internal ones are curved inwardly, the lateral and spiracle ones are evidently longer than the anteromarginal processes. The anterior lateral processes of the meso and metothor&x are by 1/3 shorter than the posterior ones. The lateral processes of the abdomen from the 1st to the 5th are gradually decreasing In size towards the back; the 6th is obviously longer than the 5th; the 8th Is longer than the 7th. The caudal setaes are heavily sclerotized; they are connate In

163 the base, with small spines Inwardly, slightly curved, and are gradually thinning towards the aplx. The caudal case Is without excrements. The claws are sharp, with a smoothed projection.

The material: Ethiopia, 30 km east of settlement Abobo; 20.11.1986, (L N . Medvedev), 1 larva on the leaf of Ipomoea, rearing.

Aspidomorpha areata Klug.

The description Is based on the exuvium of the larva of the last age. The lateral processes are light brown, they are widened in the base and then become sharply narrowed, getting thinner towards the aplx (Fig. 11,5). The secondary branches occur in the front and behind the lateral process; there are 4-5 long and 3-4 short secondary branches at each side. The lateral processes and secondary branches at the aplx have needle-llke thecas on their end. The microsculpture of body Integuments is light, looking like weak cross-sectional shiindes; the setae of the top are light and short, the thecas are strongly elongated and slightly serrated. The frons Is with long setae which are rounded at the aplx. The labrum (Fl,g. 111,4) Is transverse, weakly sclerotized, slightly convex In the base and rounded at the sides; the fron margin Is weakly concave and has a shallow oval notch which reveals 6 long setae on Its bottom; there are 4 splne-llke marginal setae on each side from the notch and 4 pores on the disc. The 4 dlscal setae of the main row are long and sharp-pointed, they occur obliquely. The 2 dlscal setae of the apical row are short and lie near the front margin of the labrum. The mandibles are short, triangular, with 6 denses and an Internal Incisor margin; laterally there are 2 setae and 2 pores (Fig. 111,7). The internal and external ant6eromarglnal lateral processes lie on a common base, Inwardly they are

164 weakly curved; the lateral and spiracle processes are equal. The anterior lateral processes of the meso - and metothorax are thinner, twice as short as the posterior ones, they have weak secondary branches. The lateral processes of the abdomen, from the 1st to the 5th, become gradually shorter towards the back; the l s: is twice as long as the 5m; the 1st to 4th are strongly thickened in the base; the 6th is longer than the 5th; the 7th is three times as long as the 6th; the 8th is shorter than the 7th. The caudal setas are heavily sderotized, they are connate in the base, spineless, gradually thinned towards the apix, without excrements. The claws are sharp, without any rectangular projection.

The material: Ethiopia, 30 km east of settlement Abobo, the floodplain; 20.11.1986 (L.N. Medvedev), 1 larva on the leaves of Ipomoea; rearing.

Cassida scutellaris Wse.

The body is white, oval-elongated (Fig. 11,4), with small and hard-to-distinguish setae; the microsculpture of body integuments is not well expressed. The lateral processes are short, thinner towards the apix; with small indents; on each side there are 4-5 long and thickened secondary branches. The lateral processes and secondary branches on the apix have short styloid thecas. The lateral process of the 1st abdomensegment is not longer than the half-width of the segment. The head is light in colour, the frons is with short dub-like setae. The vertex is sderotized in its posterior part as some small spines. The labrum (Fig. 111,5) is weakly transverse, light yellow, moderately scferotized; the anterior margin has a shallow and wide notch with 6 conical setae on the notch bottom, and 4 thickened and short marginal setae on each side from the notch. The disc has 4 pores; the 4 discal setae of the main row are short they from a straight row. The 2 discal setae

165 of the apical row are short and styloid, they occur near the front margin. The mandibles are light yellow, triangular, with 6 denses and a sharp Internal margin; there are 3 pores and 2 setae on the side. The sclerites of the pronotum are light In colour, unpalnted, with very small and rare light setae. The Internal and external anteromarglnal latteral processes, which ate connate In their base, are upright. The lateral and spiracle processes are equal. The meso - and metodorsum are divided by a transverse fold Into two toruses, each of them has a regular row of small setae; the anterior lateral processes are less widened In the base and shorter than the posterior ones. The lateral processes of the abdomen, from the 1* to the 5th, are gradually getting shorter towards the back; the 6th Is longer than the 5th; the 7th and 8th are equal and are both longer than the 6*. The caudal setas are light brown, brought closer together In the base and getting parallel afterwards; they are gradually thinner towards the aplx and are obviously longer than the 8th lateral process. They carry excrements as a dark dense clot. The spiracles are light brown and look like small conical tubules; on the thorax they are evidently larger than the others. The legs are light In colour, the daws are without any projection. The body Is up to 10 mm long, the head capsule is 0.75 mm wide.

REFERENCES

Chen 8 .H. Sur une laive de Chrysomelidae du Mozambique (MaaopMys octnptorB). Bud. Soc. ent. Fr.. 1934, 28. 270-271. HYDROBIOLOGIC AL EVALUATION OF THE ALVERO RIVER AND TATA LAKE.

Monakov A.V. f. ■ .. / ■ • • •• .f . ' The aim of the study was to investigate the planktonic, bottom and water plant fauna of the waterbodies as well as to reveal the feeding pattern In fishes inhabltating these waterbodies to estimate the consequences of the regulation of the Alvero river drainage.

The paper discusses the hydrobiological materials collected in the Alvero river and Tata lake from Decem ber 1986 till February 1987 using a 5 I. pfanktobathometer, Eckman-Berdge bottom grab (1/40 m2), planktonic nets, and dip nets. Fifty quantitative samples of plankton and benthos were

processed, and the diet of 140 fishes of 8 species w a s analyzed.

Results

The width of the Alvero river in the upper reaches (about 20 km above the Abobo settlement near the Dumbong village), during low water period was from 5 to 15 m. In some places the river flows among black basalt rocks branching into narrow side channels with small waterfalls. The relatively deep backwaters (down to 2.5 m) alternate with the pebbly ridges and sandy shallows. In some places the river banks are covered with silty alluvial deposits in dense arboreal-shrub brushwoods. The water is transparent (about 1.3 m by Secchi disk), dean, with a temperature of 24 to 26°C. On

167 the stony bed there are Bivalve colonies of greenish dams, Aetheria sp. (current velocity is 0.7 to 1.5 m/sec).

The plankton as such is lacking and Is represented by single specimeens of Protozoa (Arcella), the early copepodlte stages of Calanidae and Chironomidae larvae of the 1“ and 2nd Instars. The bottom fauna is relatively rich and consists of Insecta larvae (small Chironomidae, Plecoptera, Ephemeroptera, Odonata), Its biomass is from 0.3 to 1 g/m2 The river sites with rocky banks are largely occupied by small shrimps, Caridina nilotioa sp,, sometimes the small freshwater crabs (Potomanautes niloticus) are found.

Ten km downstream, near the Debl village, the banks are overgrown by shrubs, the river width is 10 to 15 m, the bed is sandy, the depth is from 0.3 to 0.6 m. The plankton, like in the upper reaches, is represented, mainly by the drift forms of Insecta larvae (Chironomidae, Heleidae, Plecoptera), their total number is up to 200 individuals per 1 m3. The bottom fauna of the river sandy bed consists of Oligochaeta ( Naididae), Odonata larvae and Plecoptera, with a population density of up to 300 Individuals per 1 m2 and biomass up to 1.5 g/m2. The trunks of flooded trees are inhabited by the larvae of Ephemeroptera and Coleoptera.

Above the Abobo settlement the river flows among maize fields. The stream width there is up to 25 m, its depth is down to 0.5 m; the bed is covered by large-grained sand, the current velocity is high. There is almost no plankton. The sample contains vegetative remains, the moulting rinds of insect larvae, and the single larvae of Heleidae. The benthos is poor (24 individuals per m2 and biomass Is under 1 g per m2 ) and consists of

168 Naididae and small larvae of Chironomidae. Masses of Hemiptera imago and Diptera larvae are found in a narrow stripe of water macrophytes, near the bank.

Below the flooded zone (its width there is 10 to 20 m) the river flows in the forest'savanna zone. The banks are steep, occasionally up to 5 metres high. Deep sites (down to 2 metres) with slow current (0.3 to 0.8 m/sec) and silted bottom are replaced by pebbly shallows with colonies of Aetheria (current up to 1 m/sec). Occasionally there occur islands overgrown with Sudanese grass hanging over into the water and some individual tufts of Eichornia grassipes. The water transparency is 0.6 metres, temperature +24°C in the morning and +26°C in the evening. This is where one can come across planktonic forms, i.e. the copepodite stages of cyclopoid, the Chidoridae of the genus A/ona, their total numbers being up to 2 thou /m 3 with a biomass of up to 10 mg/m3. There also occur the plankton stages of Chironomid larvae. The fauna of silted bottom with large plant remains is represented by chironomid and may fly larvae with a biomass of up to 0.6 g/m3

The mesoplankton of the lake (according to the census of 30.12,86) is not rich and in terms of its composition and abundance is similar to that of many flood-plain lakes of the Nile basin that are overgrown with macrophytes. Its average numbers and biomass per 1 m3 are, respectively, 27 thousand and 0.16 g with the maximum of 40 thousand and 0.27 g. These are mostly larval stages and adults of small Cydopoida of the Thermocydops genus. The numbers of Rotatoria and Cladocera (Daphnia and Ceriodaphnia genera) is extremely low - 0,3 to 1 thousand/m3 with a biomass of 1 to 3 mg/m3

169 A repeated census performed In mid-February 1987 confirmed the low numbers of zooplankton (see Table).

Table Biomass (g/ms) of zooplankton of Tata lake according to two censuses (XII-1986,11-1987)

No. o f GrouDS. s ta tio n s . M onth. Rotatoria Copepoda Cladocera Total 1 XII 0,001 0,28 0,005 0,27 II 0,10 0,25 0 0,35 2 XII 0 0,06 0,001 0,06 II 0,02 0,20 0 0,23 3 XII 0 0,05 0,003 0,05 II 0,01 0,12 0 0,13 4 XII 0 0,19 0,008 0,20 II 0,01 0,27 0 0,28 5 XII 0,004 0,19 0,02 0,19 li 0,001 0,26 0,025 0,29 _ 6 Xil 0 0,03 0 0,03 II 0,03 0,13 0,006 0,17 7 Xil 0 0 ,2 3 _ 0 0,23 II 0,01 0,25 0 0,27 8 XII 0 0,26 0 0,26 II 0,02 0,31 0 0,33 9 XII 0 0,15 0 0,15 II 0,07 0,15 0,002 0,22 10 XII 0 0,14 0,014 0,16

II 0,01 . 0,03 0,006 0,04

Footnote: mean biomass (g/m3) throughout the lake Is 0.16 In December and 0,23 in February,

170 \

Again uopepod crustaceans prevailed in the lake, i.e. Thermocyclops crassus, and Mesocyclops leuckarti, and the number of Brachionus and Asplanchna increased. Mean biomass increased from 0.16 to 0,23 g/m2. Young Daphnia lumholtzi and adults of, Ceriodaphnia cornuta were recorded.

The relative paucity of mesoplankton is essentially made up for by rich macroplankton represented by imago of smaller Hemiptera, Chaoborinae larvae and the shrimps of the genus Caridina. Trawling with an egg net revealed that the density of these animals per lm 3 averaged 250 throughout the lake, and at some sites it reached 4000. The fauna of the thickets of drifting islands is also richly represented (up to 1 thou individuals/m3), these are primarily numerous larvae of aquatic insects as Ephemeroptera, Odonata, and Coleoptera. Hence, a total estimate of the plankton and thicket fauna of invertebrates demonstrates that planktophages do not suffer from food deficiency. This has been supported by their full stomachs and a considerable proportion of the above species there (see below).

The bottom fauna (according to bottom samples) is not rich. It consists mainly of small larvae of Chironomidae and Oligochaeta (exceptionally warm-loving cosmopolitans of Branchiodrilus hortensis), and Heleidae larvae. The near-shore part of the lake in the immediate vicinity to the marshy sites with a depth of 1.5 metres occupied by poorly-washed silts with decomposing remains of macrophytes is lifeless. It is only in the central part of the waterbody on grey, well-washed silts, the density of forage ben­ thos (Oligochaetae and Chironomidae larvae) attains 1,5 to 2 thousand specimens per m3 with a biomass of 4-7 g/ m2.

171 The stomach contents of fishes

The stomach contents of the following fish species were analyzed: 1. Schilbe mystus - 27 ind. 2. Sch. uranoscopus - 11 ind. 3. Siluranodon auratus - 29 ind. 4. Glarias gariepinus - 8 ind. 5. G.anquillaris - 2 ind. 6. Brycinus macrolepidotus - 17 ind. 7. Cromeria nilovica - 20 ind. 8. Gnathonemus cyprinoides - 11 ind. 9. Hyperopisus hebe - 15 ind.

The pelagic Schilbe mystus and Sch. uranosoopus are typical insectivores, whose stomachs were filled with larvae, pupas and imago of aquatic and air-aquatic insects (Odonoata, Trichoptera, Hemiptera, Coleoptera, and Diptera). The stomachs of larger individuals may contain •*** * M fish remains (smaller members of the same family). i •

The stomach of the planktophage contains essentially the larvae of rChaoborinae, the most numerous during the observation period.

The near-bottom C/arias gariepinus and C. anquiilaris essentially keeping on marshy spots under macrophytes are known as active predators, but of the 10 individuals analyzed, fish remains 70 to 100 mm in length occur only in two (Schilbidae). In the rest the contents of densely filled stomachs is represented by large fragments of tissues of dead macrophytes forming the bed of the waterbody with individual semi-digested cells of molluscs (Gastropoda) and shrimp remains. The pelagic Alestes

172 macrolepidotus feeds mainly on the plant remains occurring on the water surface (tree leaves, bark, seeds of acacia or grasses), air, ground, and water insects (term ites, ants, hymenopterans, or bugs). It can also feed on the young fish.

The intestines of smaller Cromeria nilotica are not fully filled, and the remains of the food are concentrated in their lower third, which appears to be related to the time of capture of the fish. The contents includes algal detritus with some individual live cells of cyanophytes (Microcystis putverea, Lungbya limnetica) and individual Protozoa (Arcella). These small fish keep near macrophytes, have the lower mouth, and possibly feed on periphyton.

Of the Mormyridae, the pattern of foraging of Marcusenious cyprinoides and Hyperopisus bebe was analyzed. The former species is a typical narrow-specializing benthophage feeding on Chironomidae larvae. Judging by the stomach contents, H. bebe is a near—bottom filter-feeding planktophage, in whose diet crustaceans predominate (Ostracoda, Cydopoda, and Chydoridae). There also occur small molluscs, Chirqpomiidae Jarvae, and occasionally Imago of bugs.

Conclusions

For a substantiated prognosis of the state of the forage base of fishes and conditions of their foraging in the waterbody in question, occasional observations only during the dry season are not sufficient. Nevertheless, based on the results of the investigation of the processes of the formation of the hydrobiological conditions of plain water reservoirs of temperate

173 latitudes and observations in waterbodies (lakes and rivers) of the White Nile basin in Sudan, some considerations concerning the future water reservoir can be advanced. In accordance with the design this waterbody, with an uneven shoreline, about 2.5 thou ha in area, and mean depth of about 3 metres and maximal depth (at the dam) of 12 metres will be used during the dry season for the irrigation of adjacent croplands. This is to be a shallow, and well warmed up waterbody which can be overgrown with macrophytes forming near-shore thickets of non-regulated part of the river, and by its character, it would be similar to common floodplain tropical lakes like the examined Tata lake. Such waterbodies are largely characterized by slight mineralization, low content of the dissolved oxygen, high productivity of higher aquatic plants, poor development (or nearly complete absence) of phytoplankton and relative paucity of zoo-plankton and zoobesthos. In the zooplankton of the created water reservoir, the role of lymnophilic 1 crustacean flltrators like Cladocera, Calanoida (possibly, of the genera Daphnia, Moina, Disphanosoma, Tropodiaptomus) and some rotifers, would presumably increase as early as the second year. The zooplankton biomass may increase to about 1 g/ m3. One can expect a growth in numbers and biomass of thicket forms of crustaceans like Copepoda, Chydoridae, freshwater shrimps and phytophilous larvae of insects instead of the already non-existent rheophlllc forms. The formation of bottom fauna normally takes a longer period, being a function of the water exchange index and the rate of precipitation accumulation in the water reservoir. The roles of rheophlllc and mining forms of insect larvae (essentially of the orders Plecoptera, Ephemeroptera, Trichoptera) should be primarily reduced, and the role of the lymnopelophilic forms of the worms ( Tubifiddae, Naididae) and Chironomidae larvae, presumably of the genus Chironomus, is to increase. One could expect a considerable Increase in the biomass of "soft" (mollusc- free) benthos. Among the latter, instead of the no longer existent bivalve family of Aetheridae, an Increase in the numbers of the molluscs of the • families Sphaeriidae and Corbiculidae is possible.

On the whole, the stage of the forage base of the main commercial fishes of the future water-reservoir to be used as a fattening waterbody is expected to be satisfactory. This primarily applies to typical pelo- detritophages (species of the genera Heterotis, Citharinus) and phytophages (Distichodus oreochromis, Tila-pia). The role of pelagic fishes of the family Schilbidae and on their basis, active predators of the genera Hydrocynus and Gymnarchus may increase. Specialized benthophages of the genus Gnathonemus, Mormyrus and near-bottom planktophages of the genus Hyperopisus are expected to be well off.

It is expected that the creation of this small water reservoir would not produce a detrimental effect on the ichthyofauna of the Alve-ro river and the fish foraging conditions.

Acknowledgements.

I should like to thank all my colleagues in the Institute of Ecology and Evolution (former Institute of Animal Evolutionary Morphology and Ecology) of the RAS for their generous help in collecting the samples. Thanks are also extended to L. G. Korneva, T. L. Poddubnaya, I. K. Rivier, G. I. Markevitch, and N. I. Zelentsov from the Institute of the Biology of Inland Waters of RAS who helped me with the identification of different groups of organisms. I am

175 Indebted to V. R. Aqlekseev and N. M. Korovchlnsky for their advice in the Identification of Copepoda and Cladocera.

Ust of Invertebrate species recorded In the Tata lake and Alvero river according to the census of December 1986-Pebruary 1987

Rotatoria 1. Brachionus falcatus f, falcatus 2. B.angularis 3. B.caudatus 4. B.calydflorus 5. Anuraeropsis fissa f.punctata 6. Bpiphanes macroura 7. Lecane leontina 8. Lecane bulla 9. Trichocerca jermingsi 10. Hexarthra intermedia 11. Pilinia terminalis 12. Tetramastix opoliensis 13. Asplanchna sieboldi Gopepoda 1. Mesocyclops leuckarti 2. Mesocyclops ogunnus 3. Thermocydops crassus. Cladooera 1. Daphnia lumfalfczi 2. Ceriodaphnia cornuta 3. Paeudoaida szalayi 4. Alona sp.

176 Decapods 1. Caridina nilotica 2. Potamonautea nilotioua Oligochaeta 1. Branchiodrilus hortensis Chironomida 1. Cryptochironomus kieffer sp. 2. Chironomini Genus A. Roback sp. 3. Harniscbia kieffer sp. 4. Stictochironomus kieffer sp. 5. Nilodorum kieffer sp. 6. Polypedeium kieffer sp. 7. Chironomus Meigen sp.

177 NCIC - Printing Unit