INFLUENCE OF DRAINAGE AND EDGE VEGETATION ON LEVELS OF ATTACK AND BIOLOGICAL PERFORMANCE OF THE WHITE-PINE WEEVIL

The influence of selected ecological factors was studied in relation t o the levels of attack by the white pine weevil and the biological per formance of this insect in Norway spruce plantations. Results showed t hat in plantations growing on medium-textured soils, those situated on imperfectly drained soils supported higher levels of infestation than those on well-drained sites. The presence of shelterbelts creating an edge effect near a plantation was associated with higher levels of in festation. The biological performance of the weevil was affected by dr ainage but was not affected by the presence of shelterbelts. On imperf ectly-drained soils, adult mean weight was smaller than on well-draine d soils. The number of insects per leader was not affected by drainage regime. Adult mean weight and the mean number of insects per leader w ere not affected by the presence of shelterbelt vegetation. Host and s ite selection are discussed in relation to the biological performance of the weevil.