Einfluss von Habitatmanagement auf die Reduktion von Schadlepidopteren im Kohl

Beneficials can prevent or reduce outbreaks of pest species. To strengthen the populations of beneficials, their food sources must be improved in cultivated areas. The effects of habitat management for augmenting beneficial population on parasitism and predation rates of three lepidopteran pest species were investigated on two organic fields in Alten (Switzerland). The aim was to improve pest regulation through wild flower strips along fields and by planting Centaurea cyanus as companion plant within the crop. Strips of Centaurea cyanus and Fagopyrum esculentum increased parasitsm on the lepidopteran pests. C. cyanus planted as companion plant furthermore increased predation on the eggs and parasittism of the larvae ofMamestra brassicae. Several technical and methodological aspects still need to be improved before the approach is ready for practical use.