INCREASING THE AVAILABILITY OF FOOD AND THE REPRODUCTION OF POECILUS-CUPREUS IN A CEREAL FIELD BY STRIP-MANAGEMENT

In a 8 ha field the availability of food and the reproduction of the m ost abundant carabid beetle Poecilus cupreus L. (Carabidae, Coleoptera ) was compared between a strip-managed area (cereal area subdivided by strips of weeds and wild flowering herbs) and a conventionally treate d cereal area. Data on phenology, biometry, quantity of the gut conten t and egg production were collected during the main reproduction perio d (April-July). Females were found to be significantly larger and heav ier in the strip-managed area than in the control area. The higher wei ght (corrected for size) indicated better feeding conditions in the st rip-managed area, which was confirmed by having better filled crops. T he state of egg development and the numbers of eggs in the ovaries ind icated a prolongation of the reproduction period in the strip-managed area, whereas females caught in the cereal area contained significantl y fewer ripe eggs. The results of egg-laying tests in the laboratory s howed the same trend but did not confirm any significant differences b ecause of a high rate of individual variation. All measurements from f emales point to a higher availability of food in the strip-managed are a and to an enhanced reproductive potential at this site. For males, o n the other hand, the results did not reveal such a uniform trend.