Seasonal changes in the spatial distribution of feeding by the pine weevil Hylobius abietis in Scots pine plantations.
Studies of feeding intensity were made in 5 forest districts in Poland using the trap bolt method described earlier. Bolts were placed every 6 m along one row (25 bolts per row) at the margin (3-6 m from the edge), one in the middle (32-40 m from the edge) and one at 16-20 m from the edge of an 80-m wide 1-yr-old Scots pine [Pinus sylvestris] stand established on recently felled areas. In early May, greatest feeding intensity was near the edge and least in the middle of the stand, whereas from mid-June the pattern was reversed. Average values for 4 forest districts showed that feeding intensity during June to August was 3.1× greater in the middle of plantations than at the edge.