The creation of island habitats to enhance populations of beneficial insects.

Abstract

As a management strategy to diversify the agro-ecosystem and provide improved overwintering opportunities for natural enemies, linear island habitats were created across the centres of two cereal fields .

An investigation into the overwintering densities of polyphagous predators in the new habitats revealed densities of over 150m^-2 during the first year of establishment. Absolute sampling of the within-field habitats during the second winter (1988/89) showed that earth banks sown with certain grass species supported predator densities of over 1000m ^-2.

The effect on early season predation of artificial prey items resulting from the maintenance of a predator population within the field over the winter period was also investigated.