THE EFFECT OF TIME OF SOIL CULTIVATION ON THE INCIDENCE OF PTEROSTICHUS-MELANARIUS (ILLIG) (COLEOPTERA, CARABIDAE) IN ARABLE LAND IN IRELAND

The life cycle and seasonal adult activity patterns of Pterostichus me lanarius (Illig.) in Ireland are described. Pitfall trap catches are a nalysed using a multiple linear regression model to test the hypothesi s that time of soil cultivation influences the breeding success and po pulation production of this species. Whilst total seasonal catches wer e not strongly influenced by soil cultivation history, catches made du ring the main emergence phase of the new generation were lower in spri ng cultivated fields compared with uncultivated or autumn cultivated f ields. The analysis suggests that spring soil cultivation reduces larv al/pupal survival but that rapid inter-field dispersal by adult P. mel anarius following emergence from pupation masks the effect of soil cul tivation on individual fields.