Assessment of a commercial spider venom peptide against spotted-wing Drosophila and interaction with adjuvants

Abstract

Chemical control of insect pests in food crops is dominated by broad-spectrum insecticides from a few classes, and there is an urgent need for alternative modes of action. We examined the efficacy of a spider venom peptide, GS-omega/kappa-Hxtx-Hv1a (hereafter, Hv1a) for control of spotted-wing Drosophila and evaluated the importance of phagostimulants and adjuvants for its efficacy. Topical and residual activity of Hv1a was low, with only 17.5% of exposed adult D. suzukii dying after 72 h. In contrast, 100% adult mortality was observed after 24 h when three adjuvants were added to Hv1a. Survival of eggs of D. suzukii oviposited into blueberries was also reduced by exposure to Hv1a combined with the same adjuvants, indicating that Hv1a activity against D. suzukii in the laboratory, but requires penetration of the insect cuticle for efficacy. In a field trial in blueberries, Hv1a gave comparable control to phosmet, and significantly reduced infestation in fruit. This biopesticide adds a new mode of action to the options available for integrated pest management of this and other insect’s pests.