166 1998-1999ICIPE Scientific Report

demonstrating the importance of the former in The weevils (Curcuüonidae) show a very high overlap maintaining overall diversity inagroecosystems. Both between tlie 'true' montane forest sites, because they this and Üie surveys of pristine systems indicate that may be mucli better adapted to low temperatures. longer-term studies give a better picture of Many of tlnese Cujculionidae have closely related h3rmenopteran diversity at both specific and higher species in Europe. At Gatamayu, where another forest taxon levels. (See also Section C beknoon Agivbiodiversity) type occurs (about 300 m lower altitude), the diversity We expanded the Hymenoptera study into a is higher and shows more overlap to the typical unique 'tri-trophic' study of RBA, funded by The tropical sites, such as Forest. British Ecological Society and led by Lawrie S. Dependcint on funding, it is hoped to continue Springate of tlie Royal Botiinic Garden Edinburgh. with these studies in , including comparison of Concentrating on forest fragments in the and (more or less) primary forest stands, adjacent Machakos regions, simultaneous surveys were made secondary forests and forest fragments, in order to of producers (Angiospermae) and primary (moths - get data on biodiversity reduction under habitat Lepidoptera) and secondary (Hymenoptera) fragmentation. These data should be of interest in consimiers on a spot-sampling basis. Opportunity understanding sustainable use of forest resoiuces. was taken to train two Kenyan students in the basics of RBA during this prograimne. 9. BIODIVERSITY STUDIES AT MPALA RESEARCH CENTRE 8.1.1 Environmental impact assessment oflClPE's tsetse and fruit fly control Background, approach and objectives In collaboration with IQPE's Lethal Insect Technique Mpala Research Centre is a field station situated in (LIT) project for tsetse and the African Fruit Fly the Laikipia District of central Kenya near Moimt Initiative (AFFI) Programme, Hymenoptera were used Kenya, a region characterised by semi-arid savanna to study the non-tai-get effects of tlie application of habitat. The Centre is a collaborative project of the control agents in the Ngiuniman region. Two 10-week , National Museums of Kenyei, studies of Hymenoptera diversity were made before Princeton University, and the Smithsonian Institution. the application of Metarhizium anisopliae and baited The Centre is well situated in one of the most traps to control Glossinidae (tsetse fly) andTepliritidae biologically interesting regions within Kenya, but (fruit fly) and catches analysed- Follow-up studies almost no entomological study has been imdertaken have been made (LIT) or are in progress (AFFI). there. In addition to the specific project outputs, these Identification and analysis of material from all projects are also solidifying collaboration between ICIPE and Mpala. IQPE maintains a network of field three studies is in progress. stations in Kenya, and there are considerable potential 8.2 INSECT COMMUNITIES IN EAST AFRICAN benefits in the collaboration for both institutions, FORESTS STUDIED BY CANOPY FOGGING such as maximising use of facilities by both staff and visiting scientists. Participating scientists: T. Wagner* (Museum Koeing and University of Bonn) ('VisUmg scienUst) 9.1 INVENTORY OF MOTHS (LEPIDOPTERA) Students: Nadine Spitz (BacMorsstudent); Carsten Knap Participating scientist: S.E. Miller (Masters student); ajid Eva-Maria Levermann (PhD student), all University of Bonn, Germany Assistants: N. Onyimho and others

Donor: German Science Foundation Donor. Smithsonian Institution Collaborators: »National Museums of Kenya • Kenya Collaborators: * Mpala Research Centre • National Wildiife Service • Museum Koenig • University of Bonn Museums of Kenya • Natural History Museum (London) • Smithsonian Institution Forest canopy arthropods were sampled in January and February 1999 at various sites in Kenya, as an The inventory of the species of larger moths extension of earlier studies elsewhere in eastern Africa. (Sphingoidea, Bombycoidea, Noctuoidea, Study sites included the , Geometroidea, Zygaenoidea, and Pyraloidea) present Moimt Kenya National Park, Kikuyu Escarpment at Mpala together with data on seasonality, will (Gatamayu), Kakamega Forest, and forest fragments provide a baseline for fiuther faimistic and ecological near Nairobi. work at Mpala. It will also provide data for larger Analysis of flie material is in progress, but some ICIPE projects and collaborators, mapping the preliminary obsei-vations are possible: Tlie Gatamayu distribution of selected species in Africa. The initial and Aberdare sites belong to a (more or less) closed plan was to undertake a 1-year survey of moths at block of forests, but tlie faimal overlap of beetles Mpala Research Centre. The sampling continued over between these two sites is much lower than between 20 months because of the on-going drought, and was the two disjxmct sites, Aberdare and Mount Kenya. completed in December 1999. Specimen preparation Environmentàl Health Management•Bioáiversiiy und Conservation 167 is largely completed, but because of this extension, different branch architecture and rates of flowering sampling, identification and analysis have only begun. and fruiting. Trees with C. nigriceps residents tend to Blacklight sampling was undertaken on 24 nights be more brítnched and to have few if any flowers. To in 11 sets from May 1998 to December 1999. determine whether the eints cause such changes, or Approximately 300 morphospedes of larger moths whether they colonise trees with different attributes, (Macrolepidoptera and Pyraloidea) have been an experimental plot was established at Mpala segregated and tentative species identifications have Research Centre in which ants of each species were been assigned to over half, using the National permanently removed from some trees and not others. Museums of Kenya collection. Fiu-ther identifications Bimonthly measiures were initiated to document the will be made at the Smithsonian and the Natural number of leaves, flower buds, flowers and fruits on History Museum, London and an annotated checklist paired trees with and without ants. will be prepared; voucher collections will also be Heavy browsing by an elephant herd several distributed. This survey of moths will have the direct months into the project provided the first evidence impact of documenting a significant portion of the that the presence of ants can influence elephant insect fauna at Mpala. The study has also had indirect herbivory on A. drepanoiobium. Trees from which ants impacts by promoting other research at Mpala and had been removed suffered both a significantly greater providing material for studies. likelihood of being browsed and branch lengths removed by the elephants. 9.2 INVENTORY OF ANTS (HYMENOPTERA: Field observations and analysis are still underway. FORMiaDAE) 10. IMPACT OF FRAGMENTATION IN THE Participating scientist: R.R. Snelling (Visiting Scientist) COASTAL FOREST: CASE STUDY ON TERMITES aNSECTA: ISOPTERA) Donor: Smithsonian Institution Background, approach and objectives Collaborators: • Mpala Research Centre • National Musew7is of Kenya • Natural History Museum of Los The forest on the East African coast has existed for Angeles County (USA) millions of years and has proiided a refuge both for faimal and floral species that have evolved within it During September and October 1999, in the first of and for those that evolved outside. The resultant three visits that will allow seasonal coverage, 70 effect is a high level of endemism. species of ants in the immediate vicinity of Mpala In the past, the forest covered an extensive area Research Centre, despite the dry conditions. Detailed along the coast, but in the course of time, it has been identification of the species and prepjiration of destroyed to supply wood for fuel, building and taxonomic keys for their identification are in progress. carving. A large portion of the forest has been cleared The taxonomic information will be of immediate use to give w^ay for farmii^ and toiuist development. As to several projects already underway dealing with a result, the coastal forest remaining today exists as a ant ecology at Mpala. This is one of the few detailed series of small fragments, isolated from each other by inventories of ants at a given site in East Africa (in expanding agricultural land, degraded scrubland and contrast to West Africa, where there have been many in some areas, savanna woodland. The remaining more site-based studies). A reconnaissance visit weis forest is of great conservation interest, since it is also made to Kakamega Forest, to assess the potential surrounded by an ever increasing human population for further studies there. that seeks to convert it to farmland. Five forest fragments of different sizes were 9.3 IMPACT OF ANTS ON GROWTH AND selected for tlie termite study. These are Arabuko REPRODUCTION OF ACACIA Sokoke (size 41,716 ha), Marenje (size 1641 ha), DREPANOLOBIUM Gongoni (900 ha), Muhaka (<200 ha) and Longo Mwagandi in Shimba Hills (<100 ha). Participating scientist: E.E. Lyons (Visiting scientist) Termites are important indicators of hiunan- Collaborators: • Mpala Research Centre • National induced chcinges since their species composition Museums of Kenya changes with alteration in landuse. When forests are cleared for agriculture or other forms of human This project explores the impact of resident ant spedes development, termite species dependent on wood or on the growth and reproduction of Acacia woody litter decrease, while those with deep sub- drepanoiobium, a small tree that covers millions of terranean nests and ability to live on crops and crop hectares in East Africa, particularly on black cotton residues increase. The key objective of this study is to soils. On any given tree, one of fotu: ant species can establish and monitor the taxa of termites that live in tlie large swollen thorns {Crematogaster miynosae, habituate the fragmented forest. The taxa selected C. nigriceps, and Tetraponerapenzigi) or in the hollowed will be used for monitoring biotic response to out, dead or dying parts of the stems (C. sjostedti). anthropogenic environmental change associated with Trees with different resident ant species display habitat fragmentation and modification. Tropical Insect Science for Development

1998/99 icipe Annual Scientific Report

The International Centre of Insect Physiology and Ecology (ICIPE) RO. -Box 30772, Nairobi, Kenya; Tel; +254-2-861680-4/802501 Cover photographs, clockwise front upper right: Woman and child suffering with malaria. Coast Province, Kenya; packaging processed honey in ICIPE's Apiculture Quality Control Laboratory; woman farmer from Suba EHstrict, Kenya with new calf fed on Desmodiutn forage; lolaus icipe Collins & Larsen; Original photograph of katydid by Antony Barmister of Gallo Images, SA.

1998-1999 ICIPE Annual Scientific Report ISBN: 92 9064134 7

Published and Printed by ICIPE Science Press P.O. Box 72913, Nairobi, Kenya

Edited by: Á. Ng'eny-Mengech Editorial Assistance: D. Osogo, S. Mwanycky and A. C. Ndimg'u Typesetting: J. Kamau Illustrations: N. Mwanga Komeri and I. Ogendo Cover Design: I. Ogendo Printing Supervisor: J. Malombe

Copyright © 2000 The International Centre of Irtôect Physiology and Ecology (ICIPE). All rights reserved. No part of this report may be reproduced in any form without the written permission of the Director General, ICIPE, P.O. Box 30772, Nairobi, Kenya