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INSECTS OF THE SPERRGEBIET KARAS REGION, NAMIBIA

COMPILED BY ; Eugene Marais 1493 Namibian National collection State Museum of Namibia P.O. Box 1203 Windhoek EXUCUTlVE SUMMARY

From an ecological perspective, the Sperrgebiet is difficult too classify. Although usually regarded as situated in the Namib Desert biorne, it is really atrnasition~l area between the mild arid Succulent Karoo biome, the hyperarid Namib Desert biome, and the hot arid Narna Karoo biome. The situation is further complicated by a number of faunal provinces bordering on the area, as well as the unique character of its own fauna.

Quantified extrapolation of data on the insect fauna of the area are almost impossible, as no systematic entomological investigation of the area has been attempted, and as the insect material collected from the area are mainly unpublished, unidentified and scattered in a number of insti tutions and countries. However, the pUblished information on ~ southern were perused, and relevant information has been extracted from a number of sources. These sources indicated that: 1. The insect groups of primary ecological significance are those genera, tribes, subfamilies, and families which have reach their highest diversity in southern Africa in the African South West Arid biogeographical region (ASWA). 2. Those insect groups with a large number of endemic species in the ASWA, usually have a number of species endemic to the Sperrgebiet or its immediate vicinity. 3. Insect groups of a predominant herbivorous biology and highest diversity in the ASWA, usually have an unusual number of species endemic to the Sperrgebiet. 4. Published distribution records, especially based on old collection records, should be regarded with reservations, as the localities are often misleading or inaccurate. 5. Information about the fauna of the littoral zone, the coastal area, and the Orange River mouth area are virtually non-existent. Despite this lack of information, I still regard these areas as some of the most ecologically sensitive areas, especially in view that these areas are most severely affected by the mining activity and resultant settlement. The fauna from these areas will also constitute the principal agents for recolonizing prospective

2 rehabilitated mining areas, and a proper investigation into these faunal communities should have been available already. 6. The most reliable information on the insect fauna of specific ecotypes are from the Obib/Oaberas area, from Rosh Pinah, and from the Klinghardt mountains. 7. The Klinghardt mountains and Skilpadberg (close to Hohenfels) have resident populations of some very restricted species, while the area from the Orange river mouth to about 15 Jan upstream is suspected to harbour similar popUlations of unique freshwater species. These areas (Klinghardtsberg, Skilpadberg, and the lowermost Orange river) should be regarded as core conservation areas, access to them should be stricktly controlled, and further degradation of the habitat by human activity should be prevented. Other areas in the Sperrgebiet display similar unique populations of , but are much more resilient due to the large area of available habitat.

In general the study was severely restricted by the lack of comprehensive information on the Sperrgebiet insects, but this problem is typical for almost the whole of Namibia. However, information insects from the area was extraordinary difficult to obtain. This can partially be explained by the remoteness and inaccessibilty of the area, but the major reason is the severe restrictions imposed by various authorities since diamonds was discovered there. I am of the opinion that some of the profits from the diamond mining activity should be used to rectify the present dearth of information as quickly as possible, especially in the light of the potential importance of the C2) area as a unique refuge of genetic material. A primary goal of such an effort should be to retain the material and information in Namibia, and not to let it be exported as in the past.

It is furthermore recommended that the area should be provided with protective legislation as soon as possible, with the aim to safeguard its genetic resources while it still contain a neg legible human popUlation and a single industry. In addition, a coherent programme should be launched to collect additional data, with the additional goal to identify and safeguard core conservation areas within a larger buffer area.

3 BACKGROUND

The Sperrgebiet is generally regarded as part of the Namib Desert biome. However, it is the transitional area between the succulent Karoo biome to the south and the Namib Desert biome to the north, as well as the transition between the Nama Karoo biome to the east, the Marine biome to west, and the Namib Desert and Succulent Karoo biomes in the middle. In addition, the northern part of the Sperrgebiet represents the transition between the hyperarid, vegetationless, unconsolidated dunes of the Central Namib and the moving barchans and undulating vegetated sands od the Southern Namib. However, the first mobile major dunes of the Namib desrt occur in the far southeast of the Sperrgebiet. These dunefields of the Sperrgebiet is known be the genetic epicenter of the majority of the present fauna of the Namib biome.

In the south, the Richterveld/Huns mountains, with their known high levels of unique endemic species, intrude into the Sperrgebiet in the Rosh pinah/Daberas/Obib area. The southern border itself is the lowermost part of the Orange/Vaal riverine system, known for its distinct complex of freshwater species. In addition, the evolutionary extremes of the genetic lineages typical of the reknown Cape biogeographical province can be found in the Sperrgebiet.

The Sperrgebiet therefore harbours a Rn~~~~ial. It is a true meeting place of the insect fauna of the east and the west, of the north and the south. Although the entomological resources of the area have been poorly studied, their is abundant evidence from a number of unexpected groups to support this hypothesis.

The Namib biome as a whole, including the Sperrgebiet, are usually classified into three major habitat types or biotopes - dunefields, gravel plains and riverbeds. These divisions are not simply made on the basis of predominant substrate or geomorphological features, nor are they made to simplify habitat recognition. These biotopes have distinct faunal assemblages, and "indicator" species for these desert habitat types are usually insects, especially the highly visible

4 tenebrionid or darkling .

The individual biotopes themselves are subdivided into smaller distinct habitat types within a specific biotope; either based on habitat preferences of faunal elements within the assemblages, e.g. hummock dunes, interdune plains, mobile dunes; riparian vegetation, reedbeds, trees; etc; or into less distinctly defined habitat units (ecotypes) based on subassemblages of faunal elements and climatic, substrate or vegetation characteristics, e. g. coastal dunes, inland dunes, peripheral dune areas; or southern (including the Sperrgebiet), central, and northern Namib.

Distibutions are temporally flutd, over longer or shorter periods due to changes in environmental conditions, and species usually associated with a different ecotype or even biotope can therefore occur in adjacent areas under favourable conditions. However, core areas within the range of various species can usually be identified, from which habitat classifications can be discerned based on typical faunal subassemblages. Expected faunal subassemblages are therefore important when specific habitats and areas are investigated.

other smaller distinct habitat types, which are not always associated with a single one of the common biotopes mentioned above, can also be recognized, e. g. the littoral zone, lichen fields, temporal grass fields, etc. Each of these habitat types will again have their own typical faunal subassemblages . ..',

In the southern Namib another biotope of critical importance occur, the :;.- isolated inselbergs and mountain ranges. Similar extensive outcrops of elevated bedrock are rare in the central and northern Namib, and where they occur they are usually .s!.evoidof distinct fauna due to (!) palaeohistorical reasons.

The major concern when investigating such habitat types should be to tpentify those of limited geographical size and distinct faunal guilds. These habitat types should be the primary concern when selecting areas for conservation, as they will not have the recuperational resilience of larger areas, and their degradation are usually accompanied by a

5 loss of genetic material unrelated to the size of the area.

However, due to the dearth of systematic information for most of the remote areas of Namibia, such habitats can presently only be defined by combining information on the occurrence of geographically limited species with an intelligent assessment of the evolutionary history and physical attributes of a specific area, as well as the habitat preference and biological necessities of the species in question. The role of the Sperrgebiet in the evolutionary history of most of the endemic fauna of the African South West Arid Region of Africa, either because endemic species which radiated from evolutionary centers elsewhere in the region occur only there, or because it served as an evolutionary center for specific groups, are an important consideration in this regard. various studies have proved that endemic 'Namib' lineages has either the largest diversity and highest endemicity of --intermediate species----in the Sperrgebiet, or the phylogenetic ancestors of such species are restricted to the Sperrgebiet and areas further south. As such it is clear that the Sperrgebiet served as a major center of speciation in the past, and due to the diversity of habitat types still provide refuge to a large number of ancestral and aberrant forms.

Clear indications about the basic faunal components that can be expected to occur in any specific habitat of the Sperrgebiet are unfortunately rather limited. A lack of systematic sampling over a long period is partially to blame, but the main problem lies in the shortage of specialist identifications.

LIMITATIONS

The data provided in this report were primarily extracted from published sources, and complemented by personal observations and information about the rest of Namibia. Unfortunately I am not familiar with the whole area, especially of the coastal dune hummocks and littoral zone.

The information available on the insect fauna of the Sperrgebiet is furthermore based on relatively recent collecting by specialists

6 interested in particular groups, especially those which seems to have centers of endemicity in the area. Of particular importance are the material collected by Kock (Transvaal Museum), Endrodi-Younga (Transvaal Museum), Penrith (state Museum), Louw (State Museum) and Irish (State Museum). Additional material has been collected by Holm (Transvaal Museum) and Louw (Nasionale Museum). The earliest material of importance, and the source of the types of many of the lesser known species from the area, was collected by Schultze (Ltideritzand Aus, Berlin Museum) and Lightfoot (Ltideritzand Aus, South African Museum).

The dearth of information and specimens from the Sperrgebiet is in stark contrast to the information available on the South African side of the Orange River, and reflect the remoteness and inaccessibility of the area, as well as the severe restrictions due to the overly stringent security measures of the concession holders f~r diamond mining. However, this limited collecting is also a blessing in disguise.

There is no doubt that the Sperrgebiet is an important southern African center of endemicity and an important area for future research for ~ evolutionary biology. It harbours not only the remains of the ancestral genetic lineages of northern fauna, but also the extreme adaptations of the dominant lineages to the south, as well as important components of the fauna of the Richterveld/Huns mountain ranges and of the faunal elements of the Nama Karoo biome. Namibia therefore has the opportunity to retain control over the benefits and material results of future research into the fauna of this area, especially by retaining voucher specimens of all genetic material from the area. Control over such material is of primary importance if future development of the area are to be based on conclusions reached by reference to own resources and expertise, and not on recommendations by foreign advisors which cannot be evaluated against a good local reference base. The financial benefits of retaining research control should also not be underestimated.

The faunal accounts listed below are of necessity rather limited. As had been stated over and over, material as well as specialist identifications are rather limited. In addition, peripheral records

7 of little concern were also for the most part disregarded. The Class Insecta is huge, and inclusion af all available records would contribute little to the overall conclusions about the area. unfortunately many critical groups had to be disregarded due to various of the stated limitations.

8 SYSTEMATIC ACCOUNT Species names in italics indicate that it is known to occur in the Sperrgebiet, in bold and italics that it is endemic to the Sperrgebiet, and underlined that it is expected to ocuur in the Sperrgebiet.

ARCHAEOGNATHA At present only one species of Archaeognatha is known from Namibia (Okahandja). However, at least three specimens were collected recently from Skilpadberg, Auros mountains and Aus. The identity of these specimens are unknown. No Archaeognatha has yet been described from Namaqualand or the South African part of the southern Namib, therefore it is not inconceivable that these specimens represent new species. The Archaeognatha were found under stones on gravel slopes in the vicinity of succulents.

LEPISMATIDAE (THYSANURA) The fishmoths of Namibia have been the focus of recent attention by Irish. He collected extensively in the Sperrgebiet, and a good reference base is available at the State Museum. The list of species below do not constitute a bias due to more intensive collecting, as the Thysanura of southern Africa as a whole are known much better, and proved to be an important component of the ASWA.

Thermobia nebulosa nebulosa found under stones on coast Thermobia vallaris Under stones inland Gopsilepisma verrecunda Endemic, under dune ~ Monachina stilifera stilifera Under dune coppices Monachina stilifera schultzei Under dune coppices Ctenolepisma longicaudata Cosmopolitan Ctenolepisma terebrans Found under variety of objects, commonly on sand

9 Ctenolepisma placida Found under objects on firm sand in southern & central Namib ctenolepisma luederitzi Endemic, found under rocks and vegetation in sand Ctenolepisma saxeta Endemic, under stones on hard surface Ctenolepisma intercursa Reasonably common in Namibia, abundant under driftwood at mouth of Orange, under variety of objects Ctenolepisma parcespinata Endemic, under stones on gravel Ctenolepisma grandipalpis Very common in southern Africa Ctenolepisma pauli ani Unconsolidated dunes, to north and south too Ctenolepisma corvina Under stones, endemic to general succulent coastal area Ctenolepisma namaquensis Endemic to coastal succulent area, under stones on hard ground Sabulepisma multiformis under dune coppices, also to north

EPHEMEROPTERA, ODONATA, PLECOPTERA, TRICHOPTERA AND OTHER AQUATIC AND SEMI-AQUATIC FAUNA The aquatic fauna of the area have been poorly studied, and the Namibian fauna has been summarized by Curtis. Some information about the fresh water insects are available, but it only indicate that the more common representatives of the Orange river system occur. Some endemic insects, especially of Ephemeroptera, Zygoptera (Odonata), Coleoptera, Diptera and Trichoptera could occur in the lowermost parts of the Orange system, especially between the islands and lagoon, but this area has not been investigated due to security restrictions. The same can be said about marine littoral fauna, as it is known that two species of Canacidae (beach ) and two species of Carabidae should occur, though not recorded yet. However, as with the lowermost Orange river, access to most of the littoral area is severely restricted.

10 BLATTODEA six species of cockroach has been identified from the area by Princis, none of them endemic, and all from either Aus or LUderitz. However, at that stage there was a very limited amount of material available. A large amount of unidentified material is now available, and it is suspected that a number of endemic species should occur in the area, especially of cockroaches inhabiting dune copppices.

ISOPTERA Termites are one of the more important insect orders to be found in any arid environment, as they are the prime recycling agents of detritus, dry woody materials, dung and other dry organic material. They can also severely restrict the large ungulate numbers during regular droughts, although they also form a substantial food resource for most mammals, including many herbivores. In addition, along the coastal area some species can cause severe problems by attacking wooden structures, reflecting their ecological role. At present a limited number of species are known from the Sperrgebiet.

Bacauliotermes hainesi Occur on consolidated sand and hard ground, known to attack man- made structures. Common elsewhere. Psammotermes allocerus Common allover the area in deep sand, both dunes and consolidated sand. Common in Namib biome. Microhodotermes viator Harvester termite. Reasonably common along eastern margin of Sperrgebiet in consolodated sand, as well as in far southern Namibia. Hodotermes mossambicus Common southern African harvester termite. Known to severely reduce grass stands during droughts, especially in interdune valleys. Common in consolodated sand and hard ground.

MANTODEA, DERMAPTERA, EMBIIDINA, PHASMATODEA, PSOCOPTERA, THYSANOPTERA No definite information is available for most of these groups, and where available, the information is outdated and of Iittle

11 significance. Representatives of 11 these groups have been collected to a greater or lesser degree in the Sperrgebiet. Some endemicity can be expected in groups like the web spinners (Embiidina), the book lice (Psocoptera) and thrips (Thysanoptera). Especially Psocoptera and Thysanoptera are fairly commonly encountered, and the same evolutionary trends as in Thysanura can be expected for Psocoptera, while the endemic nature of a diversity of flowering plants will most probly lead to endemicity in thrips. The praying mantids, walking sticks, and earwigs could contain endemic groups, but these will be expected to occur closer to the coast or will have a range that will include areas outside the Sperrgebiet.

ORTHOPTERA A large number of grasshoppers, crickets and related families occur in the Sperrgebiet. A number of endemics are known to occur, but the area are inadequately sampled and the order Orthoptera inadequately studied. The listed species therefore provides only a guideline as to what occurs in the area and what can be expected, and future studies will most definetely reveal additional endemic fauna as well as species with ranges restricted to a greater or lesser degree to the Sperrgebiet. The families listed below should not be regarded as a comprehensive list, as families for which no information are available or for which only inadequate information were traced, were not listed. Of particular interest is the predominant ASWA groups, especially Lathiceridae (an endemic Namibian family), the Euryphyminae and the Lithidiinae.

STENOPELMATIDAE Maxentius At least two species are suspected to occur the one on unconsolidated dunes and the other on sandy plains.

BRADYPORIDAE (HETRODINAE) Acanthoproctus diadematus Common in arid southwestern Africa. Acanthoproctus cervinus Expected to occur Acanthoplus longipes

12 Common in Nama Karoo Hemihetrodes bachmanni Restricted to succelent Karoo. Sperrgebiet is southernmost part of its range.

SCHIZODACTYLIDAE Comicus campestris Always on hard sandy soil. Common to east. Comicus arenarius Always on coastal dunes, from Port Nolloth to Walvisbaai. Comicus capensis Always on consolidated sand. Common to north and east. Comicus calcaris Only on dunes, common to northwest.

GRYLLOTALPIDAE Gryllotalpa africana Common southern African molecricket. Frequents wetlands.

LATHICERIDAE Crypsicerus glabra Endemic. on gravel plains

PAMPHAGIDAE Trachypetrella andersonii On gravel plains. Fairly common in Nama Karoo and Namib biomes

EURYPHYMINAE (ACRIDIDAE) Catantopoides minutissimus Endemic, on sandy plains Euryphymus eremobioides Expected to occur. Pachyphymus carinatus Plegmateropsis gracilis Endemic. On sandy plains. Plegmapterus splendens Expected to occur marginally

13 LITHIDIINAE (ACRIDIDAE) A number of endemic species occur, all undescribed (Brown pers comm)

HEMIPTERA Although a fairly large amount of material is available from the Sperrgebiet, the bugs of southern Africa are notoriously poorly studied. At this stage no specific information can be given about this large order of insects, and no reasonable conclusions can be reached about the relative contribution ot the Hemiptera to the faunal assemblages of various ecotypes.

PHTHIRAPTERA, SIPHONAPTERA, AND PARASITIC BEETLES, FLIES AND BEES Ecto- and endoparasites of the fauna of Namibia are a poorly studied field, and unfortunately collected material from Namibia are still exported without specimens being returned/retained for a local database. Some endemic species are expected to occur, especially on the smaller fauna endemic to the area, e.g. rodents, reptiles, birds, insects and other invertebrates. Though unlikely, endemic parasites on larger faunal elements, e.g. ungulates, cannot be excluded due to the transitional nature of the area.

NEUROPTERA A large number of ant lions, lacewings, ribbon wings and other Neuropterans are known to be endemic to the African South West Arid biogegraphic region. Unfortunately these groups are very poorly represented in collections from the Sperrgebiet, mainly due to the special attention that should be given to collecting and mounting these . A much larger number of species, many of them expected to be endemic, can be expected to occur in the area than those listed below.

MYRMELEONTIDAE Pamares parvus Endemic antlion Pamexis namaqua Endemic to Richtersveldt

NAEMOPTERIDAE Laurhervasia setacea

14 Tjederia namaguensis Expected to occur

COLEOPTERA The dominant role played by Coleoptera in the fauna of the Namib desert, especially Tenebrionidae, is conunon knowledge. It must be remembered that the Tenebrionid fauna received an enormous amount of attention (Koch, Endrodi, Penrith and Louw) , and especially the psammophilous fauna. In that regard it is particularly important to note that conunents made Koch (1962) is outdated and superseded by a large amount of additional information, and is especially overquoted by students of Namib insects. No special attempt was made to try and list all Coleoptera known to occur in the Sperrgebiet, mainly due to the inunensity of the task and a lack of readily available information. An effort was made to collect information on groups of particular relevance, though even that is incomplete. From the list below it is clear that the groups of particular importance tend to be herbivorous and pre-adapted to remain dormant during unfavourable conditions. This conclusion is supported by the relatively large number of endemic species encountered in the Orthoptera, and it is suspected that other orders, particularly the , will eventually support this conclusion.

CARAB IDAE Graphipterus cicindeloides Graphipterus hessei Grapbipterus simillimus Endemic to lowermost Orange river valley Graphipterus tuky Graphipterus velox agilis Graphipterus sublimbatus

GLARES IDAE Glaresis koenigsbaeri All along Namib edge

OC HODAE DAE Namibiotalpa fossilis

15 Endemic to southern and central Namib Chaetocanthus insuetus Synochodaeus costatus Synochodaeus modesus

SCARABAEINAE Scarabaeus gariepinus Only southern Namib N & S of Orange river on unconsolidated and consolidated dunes Scarabaeus denticolle Endemic to unconsolidated dunes of southern and central Namib Scarabaeus penrithae Endemic to dune hummocks of Llideritz area Scarabaeus fitzsimonsi

Hammodantus psammophilus Endemic to dunes of southern and central Namib

BUPRESTIDAE Acmaeodera capicola Furthest northern end of range Acmaeodera goryi Northernmost end of range Acmaeodera gentilis Westernmost edge of range Acmaeodera kochi Endemic to Skilpadberg area ?Acmaeodera Suspected new genus collected in Aurusberg area Julodis viridipes Northern end of range Julodis desertica Endemic Julodis chevrolati indigacea Northern end of range Julodis kochi Restricted to Stipagrostis on dunes in southern and central Namib Julodis vansoni

16 Restricted to orange River valley, nost common along lowermost part Julodis brevicollis Expected, Richtersveld species Julodis sulcicollis Expected, Richtersveld species

TENEBRIONIDAE Koch (1962) quoted a high diversity of Namib tenebrionids. These numbers are persisitently used out of context. Thus he for example only listed 102 species to occur in the "southern" Namib, which included the Sperrgebiet and the Central Namib between Koichab and Swakopmund. Of this 102 species, 73 species, including 34 endemic species, occur in the Sperrgebiet. However, Koch's figure are outdated. The Sperrgebiet being is the genetic epicenter for the northern ultrapsammophilous beetles.

Afrinus adamantinus Afrinus namibensis Asphaltesthe impressipennis Arthrochora arenicola Brinckia vaga Coastal dune hummocks between Oranjemund and Walvisbaai Brinckia insularis Endemic, coastal dune hummocks Brinckia delicata Caenocrypticus deserticus Caenocrypticus phaleroides Calognathus chevrolatii Carchares granulosa Carchares macer Coastal dune hummocks Cauricara phalangium phalangium Cimicia spinipes Coastal dune hummocks Cimiciopsis castleae Derosphaerius humilis Epiphysa flavicollis Epiphysa barbata

17 Epipbysa cistopercule At present only known from the Klinghardts mountains Epiphysa latisterna Epipbysa louwrensi Eurychora alaticollis Eustolopus octoseriatus Eustolopus calcaratus Fitzsimonsium cymbium Gonopus tibialis Hirtograbies namibensis Hirtograbies longipilis Horatoma eberlanzi Horatoma carinuluta Horatoma tesselata Horatoma striolidiscus Horatoma laevis Lepidocbora pilosa Lepidocbora diapbana Lepidochora discoidalis Lepidochora eberlanzi Namibomodes rubra Namibomodes serrimargo Nemanes expansicollis On consolidated sand/soil Nicandra spinulosa Ograbies campi On coastal dunes from Oranjemund to Swakopmund Onymacris laeviceps On coastal and inland dunes of southern and central Namib Onymacris hottentotta On dune hummocks between Port Nolloth and Ltideritz Onymacris plana debilis Endemic to the southernmost dune fields of the Sperrgebiet onymacris lobi collis Endemic on Salsola hummock dunes Onymacris boschimana subelongata On stable dunes

18 Pacbynoteles scaccarium pacbynoteles comma Pacbynoteles dimorpbus pacbynoteles baagi pacbynoteles kaszabi Pacbynoteles leucinus pacbynoteles longipilis pacbynoteles namibiensis pacbynoteles kocbi pacbynoteles adamantinus Pacbypbaleria capensis Littoral Parastizopus armaticeps parastizopus diebli Endemic to Llideritz area parastizopus transgariepinus Endemic to Skilpadberg area Parastizopus litbopsopbilus Periloma alfkeni Pbanerotomea gibberosulum Pbanerotomea sericicolle Pbanerotomea imbricatum pbysadesmia bullata Sperrgebiet include major part of its range Physosterna armatipes Expected to occur marginally Physosterna torulosa Physosterna cribripes Occur along major riverbeds Psammodes lossowi Psammodes diabolica tactilis Psammodes scbultzei Psammodes eberlanzi Pytbiopus cornutipectus On consolidated sand Rhammatodes aequalipennis lonqipes Could occur

19 Stenocara dentata Could occur Stenocara inaffectata Could occur Common allover southern Africa Stenocara aenescens Fairly common in Namibia Stenocara brevicollis bethanica Restricted to western escarpment between Orange and Gamsberg Stenolamus malacodermus Stips stali Stipsostoma sculpta On consolidated sand Stridigula planiuscula Vansonium bushmanicum zophosis (Cardiosis) luederitzensis Main distribution in central and northern dune fields of Sperrgebiet Zophosis prona Frequent deep sand Zopbosis infanda Endemic, frequent sandy plains Zophosis permiscens Zophosis namibiensis Frequent deep sand Zophosis hypallaga Frequent deep sand Zophosis orbicularis Dune habitats zophosis gracilipes Littoral zone Zophosis damarensis Barren coastal dunes Zopbosis microsculpta Endemic, found on gravel plains & river silts Zopbosis pedinoides stony areas

20 zopbosls sollvaga Endemic, in sand under plants Zophosis dejeani At base of plants on sand Zophosis linnei Zopbosls adamantlna Endemic, on coarse sand and gravel Zopbosis sinesulcis Endemic, between and under rocks Zophosis boei Expected to occur, widespread in southern Africa Zophosis fortunata Could occur

CURCULIONIDAE Byamora wbltebeadl Byamora manca Byamora adversarla occidentalis Endemic to Aurus mountains Hyamora subvirens Leptostethus anatirostris Leptostetbus glabrlrostris Endemic to Aus area Leptostetbus peregrlnus Leptostetbus argentatus Leptostetbus congener Microcerus oblongus Microcerus occidentalis Microcerus grisescens Microcerus inermicollis

LEPIDOPTERA Though relatively well studied elsewhere in southern Africa, the and butterflies of Namibia is poorly studied, particularly in regard of the and butterflies of specific areas. I strongly recommend that a special effort should be made to investigate the Lepidoptera of the Sperrgebiet, as the adjacent area to the south has proved to be a treasurehouse of species. However, collecting and mounting these

21 animals properly is a major undertaking, and the best results will be obtained by contracting the Lepidopterist's Society of Southern Africa for that purpose, but on the condition that the majority of the material remain in Namibia. The members of this Society are mainly dedicated amateurs, and little conflict with institutional policies will therefore result from stringent conditions, while they will probably be eager to investigate a relatively unknown area with a large potential for unique species. However, for the same reason some effort should be made to provide financial support and to facilitate the provision of entry permits to the area. An additional advantage is the emphasis placed by this Society on obtaining information on the feeding habits of larvae, which will promote a better understanding about the ecological sensitivity of distinct areas within the Sperrgebiet.

DIPTERA & HYMENOPTERA As for many other insect orders, the flies, bees and wasps of the Sperrgebiet is relatively unknown. Many families within these orders are known to have large numbers of endemic fauna within the Arid South West African biogeographical region, but the almost complete absence of recent reviews of such families or generic groups within these large orders prevent a more comprehensive analysis of their importance to the area. As an example the bee species are listed which are expected to occur in the Sperrgebiet, together with localities from which they were recorded within the area of concern. The Sperrgebiet are part of the range where the greatest diversity of bee flies in the world occur, though the species composition within this area is almost completely unknown.

BOMBYLIIDAE

Villa turneri Aus Villa nivearia Aus Villa anthophorides Thyridanthrax niveifrons Thyridanthrax aberrans Thyridanthrax stylicornis Exoprosopa cinqulalis Exoprosopa polysticta

22 Exoprosopa gonioneura Exoprosopa corvinoides Exoprosopa tripartita Exoprosopa argentifrons Aus Exoprosopa iridipennis Exoprosopa pleroxantha Doliopteryx crocea Aus Bombylius karasanus Aus Bombylius sessilus Aus Anastoechus nitens Anastoecbus eurystepbus Aus Anastoechus phaleratus Aus Anastoecbus sericopborus Lepidochlanus fimbriatus Aus Corsomyza eremobia Corsomyza namana Corsomyza ancepsoides crocidium phaenochilum Aus Oligodranes elegans Aus Geron maculifacies Amictogeron bezzii Aus Oncbopelma pulcbella Aus Oncbopelma trilineata Aus Toxophora cyanolepida

CONCLUSIONS Impressions listed in the executive summary are not repeated.

GENERAL From an ecological perspective, the species listed above indicate that the herbivorous species of predominantly ASWA groups have exceptionally high numbers of endemics, especially if it is taken into account that these groups are not usually restricted to feeding on endemic palnts. It will be of interest to examine this observation further, with particular reference to the Lepidoptera and Hemiptera.

The primary distributions for various faunal groupings were roughly mapped on the attached figures. The maps do not necessarily compare

23 to species distributions, as an attempt was made to map dominant visual features corresponding to the distributions, taking into account that small areas of particular habitats can sustain insect populations. As I am not familiar with the whole area, the maps are also not very accurate, especially regarding the littoral zone, which should be divided into sandy beaches and rocky shore.

Figure 1. Rough map indicating sandy (tan) and gravel or rocky (green) substrate.

Figure 2. Rough map indicating littoral zone (dark blue), coastal dune hummock and gravel plains (light blue) and lowermost part of Orange river (violet).

Figure 3. Rough map indicating major unconsolidated dune areas and barchan dune tracks (brown), and major rock outcrops (green).

Figure 4. Map indicating areas of conservation concern with core areas for stringent protection (crimson), areas protected against regular access (red), and areas where limited access can be allowed (orange). Note that the same area can be graded differentially, e.g. Boegoeberg, and that additional core protection and close protection areas can therefore be added.

HUMAN IMPACT Though not asthetic, the present tracks, pits, and exploration sites in the Sperrgebiet had little effect on the insect fauna. However, the mining activity is bound to have had a large impact, although to which degree is unknown. The human population likewise has had little effect, as most of their activities are dictated by the mining activities on whose sufferance they stay there. However, this situation may change in future if the horticultural potential of the Orange river are exploited, or if migrant stock feeding is resumed or even farms llocated along the eastern border. The envisaged introduction of ecotourism is also a potential error, as conservation issues of the Sperrgebiet are at present not legislatively protected,

24 and therefore dependent on the vagaries of subjective decisions. The area should be regarded as one of the most improtant conservation areas of Namibia, and suitable legislation for that purpose should be introduced.

TOURISM The area is considered as a tourist venue, as it encompasses one of the last pristine but accessible wilderness areas of Namibia. In additiona, several known tourist attractions exist in the area (Bogenfels, ghost mining towns, etc.). Considerable pressure could therefore develop for opening the area for tourist operations if the present stringent security measures are relaxed. However, such tourism should be strictly controlled, and for most of the area discouraged. Some routes, e.g. to Elizabethbay and Bogenfels, or to the Obib/Daberas area from Rosh Pinah, could be opened. However, general access to the area should be prohibited, except for authorized scientists and conservation officials, until the most sensitive conservation areas are recognized. To alleviate development pressure in the short term, the much more resilient Central Namib sand sea to the north should be opened for guided tourism. That unconsolidated and almost vegetationless sand sea are much less fragile than the vegetated dunes, dune hummocks, gravel plains and mountain ranges of the Sperrgebiet.

MINING Diamond mining, on a smaller or bigger scale, will probably continue until the last diamond is extracted. It will be impossible to hamper individual or institutional greed. However, with some foresight and at a larger expense the strip mining activities can be made more habitat oriented. Though late, such measures will hopefully result in some protection for the coastal area.

An alternative will depend on measures to rehabilitate stripped areas to partially resemble their previous soil profiles. It will depend on advance planning for areas to be mined and the minimum infrastructure required, as well as to redirect suitable soil cover to mined areas. In addition, core refuge and recolonization areas should be left within mining areas, to be mined at a much later stage. Such a programme will entail:

25 1. Studying the soil/sand cover of prospective mining areas in depth for future rehabilitation. 2. Advance planning of mining area layout, with inclusion of core recolonization areas (strips of pristine land within mining area) and partial resettlement of plant cover from mining sites to rehabilitation sites. 3. Advance planning of access roads, equipment pools and extraction plants to cause minimal disturbance and to serve maximal areas, with particular concern to environmental issues. 4. Sequential replacement of soil/sand cover in stripped areas to recreate initial soil profile, with such areas to border on recolonization core areas. Partial replacement of plants from areas to be mined in future. 5. Monitor fauna and flora of recolonization areas and rehabilitated areas in order to allow maximal resettlement before recolonization areas are mined.

LITERATURE The references listed below were used as a basis for the approach to this report, illuminating the role of the Sperrgebiet in insect evolution and biogeography.

- Endrody-Younga, S. 1982. Dispertion and translocation of dune specialist tenebrionids in the Namib area. Cimbebasia A5: 257 - 271

Endrody-Younga, S. 1986. The Cardiosis evolutionary lineages of the genus Zophosis. Cimbebasia A7(12): 209 -233. (Evoolution and biogeography)

Irish, J. 1990. Namib biogeography, as exemplified mainly by the Lepismatidae. In: Seely, M.K. (ed) Namib ecology: 25 years of Namib research. Transvaal MuseumMonograph 7: 61 - 66.

Koch, C. 1962. The Tenebrionidae of southern Africa 31. Comprehensive notes on the Tenebrionid fauna of the Namib Desert. Annals of the Transvaal Museum 24: 61 - 106.

Louw, S. 1986. Revision of the Microcerinae with an analysis of their

26 phylogeny and zoogeography. Memoirs van die Nasionale Museum Bloemfontein 21.

Penrith, M-L. 1986. Revision of the Zophosini Part 10. Cimbebasia A6(10): 417 - 502. (Evolution and biogeography of Zophosini)

Penrith, M-L. 1986. Relationships in the tribe Adesmiini and a revision of the genus Stenodesia. Annals of the Transvaal Museum 34(13): 275 - 302. (Evolution and biogeography)

Rutherford, M.C. & westfall, R.H. 1986. Biomes of southern Africa - an objective categorization. Memoirs of the Botanical Survey of 54.

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