Groenbeheer en plaag(bestrijdende) insecten nabij kassen in de gemeente Westland

In this project the effect of regular maintenance of road-verges and natural maintenance of the “Poelzone” on populations of pestinsects, their natural enemies and host plants has been studied. In the studies locations in the Poelzone the number of hostplants, natural enemies, pest species and neutral herbivores is slightly higher than in the regular managed road verges. The number of pest thrips individuals is lower than the number of neutral thrips species, but total numbers of thrips are higher in the regular managed verges. Pest species and natural enemies have been found on various host plant species, often on similar species. Thrips species and their natural enemies reach their maximum occurrence simultaneously. The studied locations along water banks have similar insect populations but are relatively rich in early flowering species. The studies locations in the Poelzone seem to have a slightly better balance between pest and regulating species compared to locations in regular managed road verges, but differences are small and in both management types pest species have been found. Suggestions for further research have been presented.