Annual Report for 1999
Last updated: 27 February 2000
Review of the Afrotropical Fauna of the Family Dolichopodidae (Diptera) based on the Collections of the Royal Belgian Institute of Natural Sciences and the Royal Museum for Central Africa (Tervuren).I.Ya. Grichanov
Supported by Belgian Office for Scientific, Technical and Cultural Affairs (15 March 1999 – 14 March 2000).
Project leader: Patrick Grootaert,
Department Entomology, Royal Belgian Institute of Natural Sciences, Vautierstraat, 29, B-1000 Brussels, Belgium. Tel. 32.2.627.43.02 - Fax. 32.2.646.44.33. E-mail [email protected]The main aim of the Project was to study fauna of dolichopodid species from South and Tropical Africa and Indian Ocean islands, to make a forecast of changes that can occur in biodiversity of natural forest ecosystems in the nearest future as a result of technological development, overpopulation, depletion, and pollution.
During the year the work was concentrated on studying the faunal biodiversity and taxonomic status of rare and undescribed dolichopodid species from the rich collection of type material and undetermined species deposited in the Royal Belgian Institute of Natural Sciences and the Royal Museum for Central Africa (Tervuren). Most of the specimens, provided with geographical and ecological labels, were collected from tropical forests in Congo (Kinshasa), Kenya and Madagascar. Species were defined primarily on the basis of male genitalia and male secondary sexual characters; females were assigned to species groups. Morphological terminology followed McAlpine (1981).
Unidentified material from the collections of the Royal Belgian Institute of Natural Sciences and the Royal Museum for Central Africa (Tervuren) were entirely treated. All the primary type material (several hundred specimens) was studied. During the last year (approximately) 7000 specimens of Afrotropical Dolichopodidae from Tervuren Museum, 3000 - from Natural History Museum in Brussels, 1100 - from Natal Museum, 1000 – from Namibian Museum, 300 – from the Natural History Museum in Paris, 250 - from Tel Aviv University, 100 and less - from Zoological Museum in Amsterdam, Staatliches Museum für Naturkunde in Stuttgart, Senckenberg Museum in Frankfurt were sorted. The author was also involved in researches devoted to biodiversity of inseln mountains such as Taita Hills in Kenya and Brandberg mountain in Namibia. As a result, about 100 new species belonging to subfamilies Sciapodinae, Medeterinae, Neurigoninae, Sympycninae and Dolichopodinae have been recently described and prepared by the author for publication (Grichanov, 1999a, b; 2000a,b,c,d,e,f). More than 50 species have been placed in synonymy, many species have been replaced. The subfamily Medeterinae is the most diverse in southern Africa, in contrast to the Sciapodinae and Dolichopodinae with their great number of species in Central Africa. The subfamilies and genera studied (in addition to previously investigated by the author Rhaphiinae, Hydrophorinae and Diaphorinae) include more than 90% of the known dolichopodid species. Some data bases have been published also in the Internet (Grichanov, 1999c). At present a total of more than 700 Afrotropical species are known to occur, of which about 250 have been described by the author of this project.Adults and larvae of almost all species of long-legged flies are predators inhabiting moist substrata. Small-sized species may be saprophages in larval stage. Species of only one genus (Thrypticus) are known as phytophages living inside stems of cereal grasses. Most of the numerous species of the cosmopolitan genus Medetera are associated with tree trunks, especially in boreal forests of the Holarctic Region, where their larvae are predacious on bark-beetles (Coleoptera) and other insects – tree pests. Adults of many Medetera species may be encountered in montane regions on large stones and rocks covered by mosses and lichens and in semi-desert regions in and around rodent burrows and other ground cavities. Some of the species are widely distributed across semi-deserts or maritime territories of the Old World (Amblypsilopus munroi, Hydrophorus praecox, Tachytrechus tessellatus, Thinophilus indigenus, Thrypticus bellus). The remaining species are endemic to particular countries or parts of Africa. Southern Africa as a whole and Madagascar have a significant tropical element, with many species common with central Africa or occurring across the continental Afrotropics. The Afrotropical fauna has close relation with other biogeographical regions on the generic level. Only 10 genera of about 50 known may be regarded now as endemic of Afrotropical region. Corindia, Dactylonotus, Dytomyia and Parentia are common with Australian region, Lichtwardtia, Paramedetera and Pseudohercostomus with Oriental region. Bickelia, Craterophorus, Mascaromyia and Urodolichus inhabit western Indian Ocean islands from Madagascar to Chagos Archipelago and Ceylon. The remaining genera have Palaeotropical, Pantropical or Cosmopolitan areas. Only several representatives of typical Holarctic genera was able to cross the Sahara.
Dolichopodidae inhabiting arid territories are known to represent ephemeral elements of native faunas, strongly dependant upon precipitation and longevity of the rainy season. They distribute, with a more or less even density of population, immediately following heavy showers, aggregating, often in great numbers, around small rivulets and ephemeral pools several days or weeks later, when the ground is becoming dry.Conclusion
Many of rare species are known only from their type localities. When such species which are only known from small blocks of remnant or disturbed vegetation, their long-term survival is more problematical, especially in highly altered agricultural districts. They may be threatened, if their remnant habitats are degraded by burning, grazing, clearing or invasion by exotic weeds. Active application of chemical plant protection means, land reclamation, changes in land use technologies towards more rationalized approaches can have adverse effects on the biodiversity of natural ecosystems. I suspect that many species collected 20, 60 or more years ago will never be found on this territory. That is why a revision of Afrotropical hydrophilous fauna (including Dolichopodidae) is urgently necessary.
Within the next months my research activity will be aimed on the finishing general study of the Afrotropical Dolichopodidae. The next stage of the research will be a review of dolichopodid flies on continental scale; zoogeographic implications; refinement of family classification. Keys and data base of species for all studied genera will be published. Descriptions of at least 50 more new species will be published in the nearest future (in addition to 200 already described by the author of this report). Several more publications will be prepared. First version of a computerized catalogue for all Afrotropical species will be prepared as a Web-page for publication in the Internet.References
1. Grichanov, I.Ya. 1999a. A brief review of the Afrotropical fauna of the subfamily Medeterinae (Diptera: Dolichopodidae) with descriptions of a new genus and new species. Bull. Inst. roy. Sci. natur. Belg. Entomol., 69 : 87-112.
2. Grichanov, I.Ya. 1999b. New species and new records of Afrotropical Sciapodinae (Diptera: Dolichopodidae) . Bull. Inst. roy. Sci. natur. Belg. Entomol., 69 : 113-135.
3. Grichanov, I.Ya. 1999c. Dolichopodidae Homepage: http://www.fortunecity.com/greenfield/porton/875/.
4. Grichanov, I.Ya. 2000a. Dolichopodidae (Diptera: Empidoidea). In: Brandberg Massif. Cimbebasia, 16.
5. Grichanov, I.Ya. 2000b. New Afrotropical Sciapodinae and Medeterinae with a review of Namibian Dolichopodidae (Diptera) . Studia dipterologica, 7.
6. Grichanov, I.Ya. 2000c. New Afrotropical Sciapodinae (Diptera: Dolichopodidae) with some new synonymy. Zoosystema, 22.
7. Grichanov, I.Ya. 2000d. Afrotropical Neurigoninae and notes on the diaphorine genus Dactylonotus PARENT (Diptera: Dolichopodidae). Belgian Journal of Entomology, 2.
8. Grichanov, I.Ya. 2000e. New Afrotropical Sympycninae and redescription of European Peloropeodes acuticornis (Oldenberg) (Diptera: Dolichopodidae). European Journal of Entomology.
9. Grichanov, I.Ya. 2000f. A brief review of the Afrotropical fauna of the subfamily Dolichopodinae (Diptera: Dolichopodidae). Bull. Inst. roy. Sci. natur. Belg. Entomol., 70.