Beneficial Invertebrate Activity in Organic and Conventional Vegetable Fields in Eastern England

Beneficial invertebrate activity was assessed in 2005 and 2006 in three organic and one conventional vegetable field using pitfall and pan traps. Data was generated from a total of 208 trapping sites in cauliflower, leek, cabbage, purple sprouting broccoli and calabrese crops and 80 sites in planted field margins. More activity of epigeal invertebrates was found in Brassica fields compared with leek fields and there was more in organic than conventional Brassica fields. Activity of useful invertebrate groups in the field margins decreased with vegetation development and there appears to be a need for management of margins in order to optimise activity of the most appropriate beneficial groups for the crop planted.