Janus Pannonius Múzeum Évkönyve 43 (1998)( Pécs, 1999)

Természettudományok - Nógrádi, Sára–Uherkovich, Ákos: Studies on the caddisflies (Trichoptera) of the Gemenc Landscape Protection Area (Duna–Dráva National Park), South Hungary

70 A JANUS PANNONIUS MÚZEUM ÉVKÖNYVE 43 (1998) Some notes on dominance and phenology The material of the Gemenc light trap is suitable for studying the dominance relations and the activity of caddisflies of the area examined. The summarized quantity of four species make up 97 % of total material. The females of two hydropsychids (Hydropsyche bulgaromanorum Mai. and H. contubernalis McL.) amount to two thirds of the captured material (see also Table 4). The females of these species cannot be distinguished from each other. The males of these two species also reach high dominance (14.27 %), and Neureclipsis bimaculata L. was also very frequent (2372 adults = 13.18 %). The fourth species was Limnephilus flvicornis F. As to the activity of adults, two main types can be assigned. The first, larger group contains species which are on wing continuously from May till September or October with maximal activity in June or July. Hydropsyche contubernalis, H. bulgaromanorum, Neureclipsis bimaculata and Oecetis ochracea have such type of activity (Figs. 4a-c). On the contrary, other species having a summer diapause are on wing in late spring, early summer, and later on in the autumn months. Sometimes the first swarming is very short and it cannot be detected by light traps; the adults retire soon, e. g. Limnephilus flavicornis (Fig. 4d), and other Limnephilus species. Summary The area of the Gemenc Landscape Protection Area and its environs is poor in caddisflies, with only 40 species occurring here. The community of River Danube is rather monotonous due to pollution and low oxygen content, though some more interesting species live outside the protected area, in less polluted water bodies. Further species are to be expected from canals: Dunavölgyi-főcsatorna, Ferenc Canal, Vajas-fok Canal etc. Almost all of the endangered and vulnerable species have disappeared from the area, the bulk of those still found there are not threatened. Acknowledgements Authors express their sincere thanks for the natural protection authority .... Fig. 4. Activity of Hydropsyche bulgaromanorum (a), H. contubernalis (b), Neureclipsis bimaculata (c) and Limnephilus flavicornis (d) by the data of Gemenc light trap, 1984-1985. 4. ábra. A Hydropsyche bulgaromanorum (a), H. contubernalis (b), Neureclipsis bimaculata (c) és a Limnephilus flavicornis (d) rajzási aktivitása a gemenci fénycsapda adatai alapján, 1984-1985.