Ecosystem diversification to encourage natural enemies of cereal aphids.

Abstract

In order to enhance the predatory potential of native natural enemies of cereal aphids, such as certain species of Carabidae, Staphylinidae and Araneae, overwintering habitats were created in the centres of three cereal fields. These habitats recreated the important features of natural field boundaries necessary to support high densities of overwintering predators.
Successional change altered the balance of predator community structure from initial dominance by pioneer species to more permanent specialised species. By the third winter, the predator communities were dominated by species normally restricted to overwintering in established natural boundaries.

Studies on predator emigration showed that the overwintering predator populations from the new habitats could influence dispersal patterns in the spring, providing an even spread of predators throughout the crop early in the season.