Flight periodicity and infestation size of Sitona lineatus

Abstract

SUMMARY Sitona lineatus displays two distinct flight periods; a post‐teneral flight in the late summer and a post‐diapausal flight in the spring. The late summer flight begins as soon as adults start to emerge from pupal cells during late July and continues until mid‐October. Maximum aerial density is observed in late August. Less than 10% of newly emerged adults leave the crop by flight, the rest remain in the soil or move to overwintering sites by walking. Spring flight begins in late March if temperatures are above the 12.5°C flight threshold and reaches a peak in mid‐April. Most migratory flight is downwind. Little trivial flight occurs and once individuals have located a crop, redistribution is by walking. Laboratory studies indicate that adults fly most often during the day, particularly at noon. The size of infestations appeared to be independent of the area of legumes grown in a locality with large differences occurring even between neighbouring fields. Examination of the yields of field experiments at Rothamsted demonstrate an unexpected trend for higher yields in later sown spring bean crops. This may be because late sowing avoids infestation by spring migrants.

Investigations of the host feeding preferences of Sitona weevils found commonly on white clover (Trifolium repens) in the UK

“…Hamon et al (1987) described two distinct flight patterns for S. lineatus, a postteneral flight in late summer and a post-diapausal flight in the spring. In the case of S. lineatus and S. hispidulus there were few differences in the acceptability of food material when offered instead of white clover.…”

“…This was almost certainly due to the migratory behaviour of this weevil species. Hamon et al (1987) described two distinct flight patterns for S. lineatus, a postteneral flight in late summer and a post-diapausal flight in the spring. It is this latter flight pattern lasting from late March to early June which appears to have coincided with the emergence of the plant species under test in the field in the present work.…”

Spring dispersal of Sitona lineatus: the use of aggregation pheromone traps for monitoring

“…S. lineatus colonises annual leguminous crops in the spring, either by flight or in the case of low temperatures by walking (Hans, 1959;Fisher & O'Keeffe, 1979;Hamon et al, 1987). Egg-laying starts immediately if the weevils have previously foraged on perennial legumes.…”

Identification of potential natural enemies of the pea leaf weevil, Sitona lineatus L. in western Canada

“…Larval feeding reduces seed protein content, especially in nutrient‐poor soils, and the amount of nitrogen returned to the soil (Doré and Meynard 1995; Corre‐Hellou and Crozat 2005). Control of S. lineatus using insecticides is difficult as a result of its high fecundity (Jackson 1920), migratory behaviour (Fisher and O’Keeffe 1979; Hamon et al. 1987), and concealed larval habitat (Jackson 1920); however, the egg stage of S. lineatus is prone to mortality.…”

“…In autumn, S. lineatus adults migrate to shelter belts where they consume foliage of secondary leguminous hosts like alfalfa (Medicago sativa L., Fabales: Fabaceae) before overwintering (Jackson 1920;Schotzko and O'Keeffe 1988). In early spring, adults migrate to their primary hosts, pea and bean crops, and feed on seedlings (Stein 1972;Fisher and O'Keeffe 1979;Hamon et al 1987;Landon et al 1995). After mating, females oviposit over the soil surface (Jackson 1920;Hoebeke and Wheeler 1985).…”