A 5-year comparison of overwintering polyphagous predator densities within a beetle bank and two conventional hedgebanks.
Overwintering polyphagous predator density and composition was compared within a mid-field overwintering refuge ('beetle bank') and two conventional hedgebanks over a 5-year period. During the study predator densities in the beetle bank were similar to or greater than those in the conventional hedgebanks. Whilst predator densities remained relatively stable in both of the hedgebanks over time, densities fluctuated significantly within the beetle bank. Many of the species recorded on the beetle bank are considered to be important predators of cereal aphids. The results are discussed in terms of the implications of creating such a habitat for the biological control of cereal aphids.