Flowering crops as nutritional resources for Ascogaster quadridentata (Hymenoptera, Braconidae) and other beneficials in agroecosystems

Abstract: Various flowering crops (buckwheat, Phacelia, mustard, parsnip, flax, Viper’s bugloss) were evaluated for their potential to support natural enemies and pollinators in small scale field trials. Potential impact of these plants on survival and parasitism capacity of the braconid Ascogaster quadridentata, a key natural enemy of several tortricid pests, was assessed. Furthermore, flower visitors (natural enemies, pollinators) were documented during the peak flowering period of these plants. A. quadridentata survived better and parasitized more hosts when provided with parsnip and flax. Parasitoid wasps were more attracted to water traps placed in mustard, Phacelia and buckwheat, whereas honeybees were significantly more captured in water traps placed in Viper’s bugloss and Phacelia. Syrphids, but also wild bees (Bombus, Halictus), were better documented as flower visitors by direct visual observation.