Light-trapping of Trichoptera at the March, a lowland river in Eastern Austria
Waringer, Johann; Graf, Wolfram
Adult Trichoptera were caught from 26 September, 2001 to 7 November, 2002 at the banks of the March River at Angern, Lower Austria, using a Jermy-type light trap. From a total of 36,780 specimens caught, the most abundant species were Hydropsyche bulgaromanorum Malicky, Hydropsyche contubernalis McLachlan, Setodes punctatus (Fabricius), Ceraclea dissimilis (Stephens), Ceraclea albimacula (Rambur) and Hydropsyche modesta Navas. In five out of the thirteen most abundant species the sex ratios significantly differed from 1:1, with an excess of males in H. modesta and S. punctatus and an excess of females in Agapetus laniger, Orthotrichia costalis and Ecnomus tenellus. Of the meteorological parameters tested, only sunset and midnight air temperatures as well as precipitation had significant (P < 0.05) effects on total catch. The longitudinal classification of the sampling station based on species-specific zonal distribution patterns of caddisflies yielded highest scores in the epi- and metapotamal region.