The influence of Shelterwood density on Hylobius abietis (L.) occurrence and feeding on planted conifers

Abstract

Damage to planted conifer seedings was assessed and numbers of adult pine weevils (Hylobius abietis) were estimated after cutting of a mixed conifer stand to form shelterwoods of eight different densities. Untreated and insecticide treated seedlings of Picea abies and Pinus sylvestris were included in the experiments. Both seedling damage and pine weevil occurrence were considerably higher on clear‐cuttings and in shelterwoods of low densities ( < 80 stems ha‐1) than in shelterwoods with 320 or more stems ha‐1. In shelterwoods with 80–160 stems ha‐1 feeding damage was low despite of high catches of pine weevils. Pine weevil damage on seedlings in shelterwoods is discussed in relation to solar radiation, vegetation cover and weevil behaviour. The use of shelterwoods is suggested as a practical method for reducing pine weevil damage.