Conservation Evidence: Evidence Data

Collected Evidence: Collected Evidence: Create beetle banksNatural enemies in fields: Six studies from Canada, the UK and USA (three replicated, controlled, of which two were also randomised) examined the effects on predator numbers in adjacent crops. A review found that predators increased in adjacent crops, but one study found effects varied with time and another found no effect. Two studies found small or slow movements of predators from banks to crops. One study found greater beetle activity in fields but this did not improve pest predation. Natural enemies on banks: Four studies and a review found more invertebrate predators on beetle banks than in surrounding crops, but one of these found that effects varied with time. Eight studies from the UK and USA (including two randomised, replicated, controlled trials and two reviews) compared numbers of predatory invertebrates on beetle banks with other refuge habitats. Two studies found more natural enemies on beetle banks, but one of these found only seasonal effects. One review found similar or higher numbers of predators on beetle banks and four studies found similar or lower numbers. Pests: A replicated, randomised study and a review found the largest pest reductions in areas closest to a beetle bank or on the beetle bank itself. One review found fewer pests in fields with than without a beetle bank. Economics: One replicated, randomised, controlled trial and a review showed that beetle banks could make economic savings if they prevented pests from reaching a spray threshold or causing 5% yield loss. Beetle bank design: Two studies from the UK found certain grass species held higher numbers of predatory invertebrates than others. Crops studied were barley, field bean, maize, oats, pea, radish, rapeseed, soybean, wheat and pasture.Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F729https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F729Thu, 30 May 2013 14:45:59 +0100