S. Mahunka szerk.: Folia Entomologica Hungarica 54. (Budapest, 1993)

FOLIA ENTOMOLOG ICA HUNGARICA ROVARTANI KÖZLEMÉNYEK LTV 1993 p. 93-100 Seven new Trit hoptera from the Gombák River system, Malaysia By J. Oláh (Received February 14,1993) Seven new Trie hop tera from the Gombák River system, Malaysia. - The Sungai Gombák river system in Malaysia is well studied compared to the general state of tropical rivers. The species structure of its aquatic insect communities is however almost unknown. Seven new Trichoptera species are described and figured: Agapaus limsusan sp n, Chimarra kuala sp n, Drepanocauron malaya sp n, D.limorum sp n, Adicella dahsetuha sp n, Diplectrona gombák sp n, Dinarthropsis brevipennis sp. n. Introduction The Sungai Gombák river system in Selangor state of Malaysia belongs to those few tropical rivers which are relatively well studied (Bishop 1973), but not their species structure. The presumably rich caddisfly community, similarly to other groups of aquatic organisms is almost unknown. During December of 1991 while I was helding lectures at the University of Malaysia on nitrogen metabolism of aquatic ecosystems I could spent only one day collecting adult caddisflies along its tributaries and along the main stream. Seven species were collected and all of them proved to be unknown. Their descriptions follow. Twenty years after Bishop* detailed survey on the environment and on the gross community structure, the lower catchment area of the river is further disturbed by tin mining and highway construction. Numerous habitats and microhabitats have been destroyed. Their living communities are disappearing or becoming extinct forever. One day collecting effort including daytime sweeping and singling along springs, small side streams and bigger streams plus night time lamping with bright light yields usually much higher number of species than the seven I have collected in the rich stream network of the Gombák River system. This however does not necessarily mean that this low species diversity is the result of the habitat degradation. According to anecdotal information from field collectors and emergence trap record (Flint 1991) December is just the month which is characterized by low flying aquatic insect density and minimal emergence activity, at this tropical latitude. Types are deposited in the Hungarian Natural History Museum, Budapest. Right wings of holotypes are mounted as dry microscopic preparations. Caustic-potash treated abdomen of holotypes and the remaining parts of their bodies are stored separately in simple air-tight vials filled with 70% ethanol.