Aphid feeding of predatory Staphylinidae on different strata (soil surfaceand wheat seedlings) in laboratory experiments

The capacity of predatory staphylinid species to feed on cereal aphids (L2/ L3 of Metopolophium dirhodum) was measured in the laboratory at room temper ature, with 17 specimens of each staphylinid species tested in Petri dishes , and 45 specimens on plants, at the average. Of 21 species studied, five d id hardly eat any aphid. Eleven species ate remarkable aphid numbers in Pet ri dishes only (3.5-30 aphid nymphs per individual of a staphylinid species and day), but not on erect plants. Only Paederus litoralis and four Tachyp orus spp. were climbing onto the plants to prey on aphids (10-22 aphid nymp hs per individual of a staphylinid species and day). Also larvae of T. hypn orum were found climbing on plants, eating 2-10 aphid nymphs per day. In T. hypnorum adults, the number of aphids eaten by adults per day was high in early summer and diminished significantly in the course of the summer seaso n (at the end of the old, and the beginning of the new adult generation). T he ecological and practical significance of the findings is discussed.