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 melanarius (Illig.) in Ireland are described. Pitfall trap catches are analysed using a multiple linear regression model to test the hypothesis that time of soil cultivation influences the breeding success and population production of this species. Whilst total seasonal catches were not strongly influenced by soil cultivation history, catches made during the main emergence phase of the new generation were lower in spring cultivated fields compared with uncultivated or autumn cultivated fields. The analysis suggests that spring soil cultivation reduces larval/pupal survival but that rapid inter-field dispersal by adult P. melanarius following emergence from pupation masks the effect of soil cultivation on individual fields.