Flower Strips as Winter Shelters for Predatory Miridae Bugs

Biological control by habitat management, which uses the principles of functional biodiversity, is a promising technique for pest control in organic greenhouse horticulture. This technique consists of establishing specific host plant species which attract, house and feed indigenous arthropod predator and parasitoid species around crops. Previous studies have shown that certain species of host-plants (i.e., Calendula officinalis, Geraniaceae spp. and Lamiaceae spp.) can support naturally-occurring populations of Macrolophus spp. and Dicyphus spp. (Lambion, 2011). Trials were established in 2012-2013 to determine the potential of these host plants as overwintering shelters for Dicyphinae in greenhouses. We observed that these host-plant strips were colonised very quickly by Dicyphinae in the spring, and provided shelter in greenhouses during the winter, when prey were rare. Collaborative work with producers has led to the development of management strategies for these strips to force Dicyphinae predators to move from the host plants into adjacent crops.