The use of pheromone traps for monitoring the spring dispersal of the striped leaf-margin weevil Sitona lineatus L. (Coleoptera, Curculionidae).
This paper was presented at the Scandinavian Plant Protection Conference in Malmo on 25-27 October 1988. Sitona lineatus dispersed from perennial leguminous crops (clover and lucerne) in Denmark in 2 distinct periods. Two-thirds of the population dispersed during the 1st sunny period when maximum daily temperatures exceeded 15.5°C and wind-speed was low; the rest of the population did not disperse until 1 month later. The 1st period of dispersal occurred before the germination of the spring-sown summer host Vicia faba; accordingly, the weevils dispersed throughout the landscape. Infestation of the field bean crop occurred in 3 major invasions over a period of 3 weeks. Aerial yellow sticky traps and pheromone cone traps placed on the ground were good indicators of the dispersal when situated at the overwintering sites adjacent to the summer crop. Pheromone traps were highly selective, but sticky traps were not, making weevil counts difficult.