New records of helicopsyche bacescui (trichoptera, helicopsychidae) from the Balkan peninsula with notes on its habitat

Abstract

The species Helicopsyche bacescui in Europe has a disjunct area that is mainly situated south of 45 degrees N latitude and east of 22 degrees E longitude with an isolated smaller part in southwestern Hungary. Recent investigations on the territory of Serbia documented the presence of H. bacescui at 39 localities south of the Danube. The known area of the species is thereby enlarged by about 30%, while its western boundary is relocated by about 440 km. H. bacescui is primarily found in lowlands at elevations of less than 200 m above sea level, frequently in streams that periodically run dry. In Serbia, on the other hand, it is found in permanent highland streams at localities with average elevation of 467 +/- 35 m above sea level. The highest locality at which this species has been found is the spring of the Obudojevica (Western Serbia), which lies at an elevation of 1060 m above sea level. H. bacescui belongs to specific benthic communities that differ from typical macrozoobenthos assemblages found in similar habitats in Serbia by the pronounced dominance of Gammaridae, significant presence of Pisidium species, and absence of other groups of Trichoptera (above all, members of the family Hydropsychidae).