A MODIFIED PITFALLTRAP FOR CAPTURING GROUND BEETLES (COLEOPTERA: CARABIDAE)

A modified pitfall trap study was carried out in winter wheat growing in Straszewo village (54 degrees 10'N, 17 degrees 21'E), Poland. The objective of this study was to compare the functional effectiveness of traditional pitfall traps with those that have a plastic funnel. Ten traps of each kind were used. Specimens were collected from May to July 2006. Cumulatively, 1,866 specimens belonging to 38 ground beetle species (Coleoptera: Carabidae) were trapped. In traditional pitfall traps, 31 species and 1,115 specimens were captured, whereas in modified traps 33 species and 751 specimens were collected. The average catch efficiency of traditional traps (1.5 +/- 0.7 specimens per trap per 24 hours) was significantly higher compared to that of modified traps (1.0 +/- 0.3 specimens per trap per 24 hours). Considering the habitat and trophic and hygro-preference aspects, the collection of particular groups of specimens, both quantitatively and qualitatively, was similar for both trap variants. The average body size of ground beetles and mean individual biomass values (63.5 mg for beetles in traditional traps compared to 57.6 mg for beetles in modified traps) were not significantly different. However, significant differences were detected for total biomass (7,100 mg in traditional traps versus 4,300 mg in modified traps). Nineteen lizards (Lacerta sp.) were caught in the open traps throughout the study period, while only five specimens were taken in the funneled traps.