The effect of cereal and grass management on staphylinid (Coleoptera) assemblages in south-west Ireland.
The effects of different cereal and grass management regimes on summer staphylinid assemblages were examined in hay meadows, lightly grazed pastures, silage fields, spring cereals and winter cereals with routine pesticide application in 1986 in the south-west of the Irish Republic. Pitfall traps and a D-vac suction sampler were used. Large differences in the staphylinid populations were observed between undisturbed meadows and pastures without cultivation, cutting, heavy grazing or fertilizer use (7.0 species on average including Tachyporus dispar) and disturbed silage fields and cereals (4.1 species on average including Aloconota gregaria, Anotylus sculpturatus, Tachyporus chrysomelinus and T. obtusus). The latter habitat type was rapidly recolonised following physical disturbance, once a vegetative layer was re-established. The populations within second-cut silage fields, spring cereals with a well developed canopy and winter cereals (where the population included A. sculpturatus) were very similar. Dimethoate application resulted in a reduction of species diversity in cereals. There was a larger species diversity in small fields (where the population included Amischa analis and T. chrysomelinus) due to the occurrence of species otherwise rare in cereals. Propiconazole had no effect. It is suggested that rapid recolonization in heterogeneous landscapes, such as the one studied, may lessen the perceived impact of disturbance factors.