The effect of crop density and microclimate on pitfall trap catches of Carabidae, Staphylinidae (Coleoptera), and Lycosidae (Araneae) in cereal fields

HONĔK, A., 1988. The effect of crop density and microclimate on pittall trap catches of Carabidae, Staphylinidae (Coleoptera), and Lycosidae (Araneae) in cereal fields. Pedobiologia 32, 233-242 In 1987, epigeic fauna of cereal fields was sampled by pitfall traps placed in dense stands and sparsely planted or clear places within. Total catches of Carabiaae and Lycosidae were significantly (3 and 18 fold, resp.) greater at sparse than dense stands, while Staphylinidae were little affected. This applied also to catches of several individual species. The largest ones were either at the very edge between dense stand and bare ground, or on the latter; only 3 species were most abundant within dense stands. Microgeographic differences of catches were studied at 6 sites along a l,700m transect. For total lycosids, carabids, and most individual species, differences due to density of plant stand were more important than between site variation. The size of daily catches was positively correlated with daily average temperatures and/or sunshine hours. Large catches in sparse stands were apparently due to increased activity and preference for a warm microclimate.