Field and laboratory studies on money spiders (Linyphiidae) as predators of cereal aphids.

Abstract

1. Measurements of web cover, aphid availability and aphid capture were made in fields of winter wheat in West Sussex and East Anglia in 1981 and 1982. Capture efficiency was measured in the laboratory.
2. Linyphiid webs were scarce in spring but by late July they covered more than half the surface area of the field.
3. Cereal aphids formed 12% of the prey observed being eaten by linyphiids, and this was in agreement with the proportion of aphids amongst falling insects.
4. The estimated mortality of Sitobion avenae (F.) due to linyphiids reached a peak of 31 m^-2 day^-1 during flowering and then declined. There was a considerable amount of aphid movement early in the season and it is concluded that spiders would make a significant contribution to aphid control if web cover could be increased in the spring.