Spatial relationships between carabids and pest larvae in a winter oilseed rape crop

Abstract

Studies in the EU MASTER project show that carabid beetles can feed on larvae of oilseed rape pests (e.g. Piper & Williams, 2004), but to identify them as potential biocontrol agents it must be shown that significant numbers encounter the prey in the field. In this two-year study, the spatio-temporal relationships between carabids and cabbage stem flea beetle (Psylliodes chrysocephala) have already been reported (Warner et al., 2003). Now, we compare carabid distributions with those of pollen beetle (Meligethes aeneus), cabbage stem weevil (stem weevil) (Ceutorhynchus pallidactylus) and cabbage seed weevil (seed weevil) (Ceutorhynchus assimilis) larvae dropping to the soil to pupate.