Effects of hedgerow restoration on natural enemies, pests, and pest control in intensive agricultural landscapes

Hedgerows of native California shrubs and perennial grasses bordering rotational field crops were examined for the abundance of beneficial and pest insects compared to fields with semi-managed weedy field margins.  During 2-years of sampling in the Sacramento Valley (2009-10), hedgerows attracted more beneficial insects than pests, resulting in slightly higher biocontrol of stink bug egg masses (Euschistus conspersus) by the parasitoid wasp Trissolcus basalis, in adjacent processing tomato fields. We conclude that replacing weedy areas on field crop edges with managed hedgerow plantings will increase beneficial insects rather than pest insects on farms and enhance biocontrol of pests in adjacent crops.