INTERCROPPING CABBAGE WITH CLOVER - EFFECTS ON GROUND BEETLES

Intercropping is used to reduce pests and diseases by decreasing their establishment or performance on the crop, and by enhancing antagonist activity. The effect of intercropping cabbage with white and subterra nean clover on epigeic predator activity-density was studied in two su ccessive years in the Netherlands. The presence of clover as an interc rop resulted in significantly higher predator activity-densities and d iversity, especially early during the growing season. Several carabid species, in particular Pterostichus melanarius, Agonum dorsale, and Am ara similata, were affected, whereas in the staphylinids, Philonthus s pp, showed a strong preference for intercropped plots. The contributio n of these predators and their larvae to pest suppression and the effe ct of scale in determining the final result of intercropping is discus sed.