The contribution of beetle banks to farmland biodiversity.

Abstract

The intensification of arable production in recent decades has led to a simplification of the farm landscape, with a resultant loss of many invertebrates, birds and mammals. The provision of herbaceous strips alongside field edges is one way of re-instating non-cropped habitat for many of these organisms. A different design, that of raised grassy strips within field centres, 'beetle banks', was devised principally for enhancing predatory invertebrate penetration into fields, and may also support a range of other taxa. This paper outlines experimental work carried out to quantify densities of such predators overwintering in beetle banks, as well as the summer abundance of invertebrates important in the diet of farmland birds. Some of these, Orthoptera and Lepidoptera, rely entirely on non-cropped fragments for continuing survival on farmland. Results suggest that beetle banks, although generally not as valuable as well-managed and long-established, botanically rich field margins such as hedgerows, can contribute a useful habitat resource that is far quicker and easier to instate than a hedgerow.