The refuge role of beetle-banks and field margins for carabid beetles on UK arable farmland: densities, composition and relationships with vegetation.

Abstract

I explored how little-studied, mid-field sown grass strips - beetle-banks - compare with conventional, botanically complex field margins for the provision of shelter for predatory Carabidae. Many species require such refuges from which they disperse into adjacent fields. I assessed absolute over-wintering, spring and summer carabid densities and composition, using destructive suction/turf sampling methods; and plant composition and successional change as these strips age, using quadrat cover measurement. Results, including relationships between these measures, suggest that beetle-banks have considerable value as reservoirs for enhancing carabid populations throughout the growing season of arable crops, for the biocontrol of pests.