Janus Pannonius Múzeum Évkönyve 35 (1990) (Pécs, 1991)

Természettudományok - Uherkovich, Ákos–Nógrádi, U. Sára: Trichoptera fauna of a typical cultivated region of the Carpathian Basin by light trap examination

30 Á. UHERKOVICH-S. NÓGRÁDI six and in 1987 hundred eighty-eight specimens were captured by us and by our light traps. In 1988 and mostly in 1989 the gradation has collapsed. Fig. 3 shows the Hungarian distribution data before 1985, during the years 1985-87 and after 1987. Its activity graph is also given (Fig. 4). Some other species had also short but violent swarming. Hydropsyche angustipennis Curt, had a violent swarming in 1987: two thirds of the total mass were captured within few days. 130 specimens of total 236 (in 7 years) of Neureclipsis bimaculata L. were captured in three days in 1987 (July 16-18). The quantity of several other species were very varied yearly (e. g. Hydropsyche contubemalis McL., H. ornatula McL., few Limnephilus species, Grammotaulius nigropunctatus Retz., Setodes punctatus F.). Fig. 4. Activity graph of Colpotaulius incisus Curt in Hungary, 1984-1988. 4. ábra. A Colpotaulius incisus Curt aktivitási diagramja Magyarországon, 1984-1988. Our opinion is that these biotops - as artifical and very disturbed ones - are never balanced. All new influences can change the composition of larval communities, some of the species can extinct temporarily or definitively. Such rather big changeability can be observed at all disturbed aquatic biotops of South Transdanubia. The natural, non-disturbed biotops have more permanent communities (e. g. brooks of the Kőszeg Mountains, Mecsek Mountains; Lake Balaton). Most of the Transdanubian waters belong to the disturbed type. Their trichopterous fauna has grown poor in its composition. The number of species is much less in the regulated and polluted brooks and streams than in natural waters. The rest of the species are some Hydropsyche (mostly H. angustipennis Curt.), Anaboliafurcata Brau., Potamophylax rotundipennis Brau., Ironoquia dubia Steph., Limnephilus afflnis Curt., L. lunatus Curt., L. rhombicus L., Grammotaulius nigropunctatus Retz., Halesus tesselatus Ramb. Beside these some lively species of stagnant waters can occur everywhere. These specis have a broad ecological suffering and they can establish themselves in almost all new, artifical ponds very quickly (within a few years). Such species are Agraylea sexmaculata Curt., Orthotrichia costalis Curt., O. tragetti Mosely (these two have not been captured at Kocsola yet), Ecnomus tenellus Ramb., Phryganea grandis L., Limnephilus extricatus McL., Ceraclea alboguttata Hag., С dissimilis Steph., Oecetis species (mostly Oe. furva Ramb., Oe. lacustris Ret. and Oe. ochracea Curt.), Leptocerus tineiformis Curt. Such or similar composition of trichopterous communities are characteristic of almost all cultivated and regulated areas of Transdanubia. This is a poor remainder of the original, natural fauna - without the sensitive species. During a longer collecting period 40-50 species can be proved. The bulk of this stand consists of common species bearing the change of the environs. Summary During a seven-years-long examination 1328 males and 3370 females of 47 species were collected at Kocsola, county Tolna, South Transdanubia. The number of speciemens of some species fluctuates considerably, the composition of caddisfly communities are unbalanced. The sensitive species have become extinct, the rest have a broad ecological suffering. Further pollution can cause a poorer community of Trichoptera. Acknowledgements The authors express their sincere thanks to f Mr. L. Uherkovich and to Mr. L. I'só for the organization of light trap collections, and to Mr. M. Simon for the operation of the light trap.