Uherkovich Ákos: A Dráva mente állatvilága I. (Dunántúli Dolgozatok Természettudományi Sorozat 8., 1995)

Nógrádi S. - Uherkovich Á.: A Dráva magyarországi szakaszának tegzes (Trichoptera) faunája. - The caddisfly (Trichoptera) fauna of the Hungarian reach of Dráva River

NÓGRÁDI S., UHERKOVICH Á.: A DRÁVA MAGYARORSZÁGI SZAKASZÁNAK TRICHOPTERA FAUNÁJA 137 modified permanently, mostly in its upper Hungarian part between Bares and Őrtilos. The water is moderately polluted, the most polluted tributary is the river Mura. Due to the quick velocity the concentration of soluted oxygen is relative high in the water therefore the fauna is diverse. Earlier we also studied the fauna of Bares Juniper Woodland. Sixty species were collected there according to NÓGRÁDI (1985). Along the river our examinations started only in 1989, when a light trap was erected above the surface of the water, near Szentborbás (see Fig. 1). This trap captured more than 21,000 specimens of 44 caddisfly species. The list of the material was already published (UHERKOVICH, NÓGRÁDI 1992a). Since 1991 we had been collected more than 90,000 caddisfly adults in 19 sites. We collected regularly on four sites (Dravapalkonya, Vejti, Drávasztára, Vízvár), where about 22,000 specimens have been collected. A light trap functioned close to the water at Őrtilos Railway Station. This trap captured almost 62,000 caddisflies belonging to 67 species. This is the second most diverse caddisfly material ever collected by any light trap in Hungary (the maximum number of species - 99 - were captured at Magyarszombatfa, see UHERKOVICH, NÓGRÁDI 1992b). The list of the total material and data of the species (sites, date, number of males and females) are given in the Hungarian text and some tables are presented with summarized quantitative list of the most important collecting sites (Tables 1-5). Now, taking into consideration the published data, 95 Trichoptera species are known along the river Drava. The most interesting species is Platyphylaxfrauenfeldi Brau., which was recorded from eight collecting sites in southwestern and western parts of Hungary. All the recorded specimens were captured since 1976. In six localities only one specimen was captured, but along the Dráva river, the species was not too rare in two sites. Further relatively rare species were also captured (Agapetus laniger Pict., Athripsodes albifrons L., Brachycentrus subnubilus Curt., Ceraclea riparia Albd., Chaetopteryxfusca Brau., Crunoecia irrorata Curt., Hydroptila vectis Curt., Orthotrichia angustella McL., Oxyethira flavicornis Pict., Polycentropus irroratus Curt., Rhyacophila dorsalis Curt, and Silo piceus Brau.). From the nature conservationist point of view the most important caddisfly species is Platyphylax frauenfeldi Brau., a remarkable element of a very diverse Trichoptera fauna. If the circumstances will not change considerably, this rich and diverse Trichoptera fauna can survive for the next decades. It is hoped that neither river training, nor construction of storage lake will exert a violent influence on the conditions of the river in the future. Authors' address: Dr. Sára NÓGRÁDI & Dr. Ákos UHERKOVICH Natural History Department Janus Pannonius Museum H-7601 Pécs, P. O. Box 347