EMERGENCE OF CARABIDAE (COLEOPTERA) FROM PUPATION - A TECHNIQUE FOR STUDYING THE PRODUCTIVITY OF CARABID HABITATS

An emergence arena method for estimation of within-field carabid recru itment from pupation is described. Use of the method is illustrated in a field plot experiment to assess the effect of time of soil cultivat ion on carabid survival in arable land. The population 'productivity' of Pterostichus melanarius (Illig.), a larval overwinterer in arable f ields, was found to be reduced by 80% following spring tillage operati ons. In contrast, Bembidion lampros (Herbst.), an adult overwinterer i n field margins, showed decreased emergence density on winter-sown plo ts. The value of the method in quantitative investigation of populatio ns in fragmented habitats is discussed.