Biodiversity strips around greenhouses to support natural enemies of greenhouse pests

Abstract: In 2024, biodiversity strips were established adjacent to twenty commercial
greenhouses in the Netherlands to enhance populations of natural enemies of greenhouse pests. Two flower mixtures were selected, consisting of annual, biennial and perennial species. One mixture was specifically designed to support aphid predators such as hoverflies (Syrphidae), lacewings (Chrysopidae) and coccinellids (Coccinellidae). The second mixture contained the same plant species but excluded those identified in literature and prior research as attractive to thrips, aiming to reduce potential pest risks. In addition, young trees were incorporated to provide early-season nectar resources. Insect communities were monitored in each biodiversity strip and compared with those in a mown grass control. Preliminary results demonstrate significantly higher abundances of pollinators (bees, bumblebees, hoverflies, butterflies) and natural enemies, including Orius spp., coccinellids, syrphids and lacewings, in both biodiversity strips compared with controls. These results suggest that strategically designed biodiversity strips can enhance populations of natural enemies and pollinators surrounding greenhouses. Ongoing monitoring will investigate the interactions between plant species, pests, and natural enemies in greater detail. The ultimate aim is to develop practical, crop-specific guidelines for integrating functional biodiversity into greenhouse production systems.