Janus Pannonius Múzeum Évkönyve 36 (1991) (Pécs, 1992)

Természettudományok - Uherkovich, Ákos–Nógrádi, Sára: The Trichoptera fauna of Magyarszombatfa, West Hungary

24 Á. UHERKOVICH—

S. NÓGRÁDI Figure 6. Activity graph of four Hydroptila species. 6. ábra. Négy Hydroptila faj rajzási aktivitása. Figure 7. Activity graph of Rhadicoleptus alpestris Kol., PoLycentropus irroratus Curt., Oligotricha striata L., Oecetis testacea Curt, and Setodes viridis Fourcr. 7. ábra. A Rhadicoleptus alpestris Kol., Polycentropus irroratus Curt., Oligotricha striata L., Oecetis testecea Curt, és Setodes viridis Fourcr. rajzási aktivitása. dry in every year (in the second half of the eighties), some of these bogs dried out maybe definitively. At Magyarszombatfa, near the light trap a relatively large bog lies. Since the beginning of eighties it dried out temporarily. In the past years its vegetation has already suffered a loss. The caddisflies of this bog have also become less frequent or become extinct. E. g. Limnephilus elegáns Curt, was a relatively frequent species in the seventies (in the first period of the light trap), in the eightiesits occurence became sporadic. In 1985 it was not captured, in spite of the fact that the light trap stood just on the site of the development of its larvae. Oligotricha striataL. has not been collected either in the final year of the examination, former it was not rare, too. 2. Canalizing of the streams. The Szentgyörgyvölgy Stream had a natural bed meandering on meadows a decade ago. In the middle of eighties the bed was regulated: geometric cross-section and straight line running was formed, just to the vicinity of Magyarszombatfa. As it well known, the artifical bed is rather unfavourable for the aquatic fauna. The number of species lessens considerably, sometimes only very few species can survive this rough intervention (Tobias 1984, Tobias and Tobias \9S4,Botosaneanu 1980). The regulation of water-courses have impoverished the Hungarian caddisfly fauna all over the country significantly in the past decades. It can be supposed that some species have become extinct in consequence of these changes. Several species developing in small