Oviposition selection, prey preference and release strategies enhance the combined aphid control effects of Aphidoletes aphidimyza and Aphidius gifuensis

Aphidius gifuensis and Aphidoletes aphidimyza are widely used in agriculture to control Myzus persicae using inundative biological control (IBC). However, it is not clear whether intraguild predation (IGP) can be overcome to achieve stable aphid control when both predators and parasitoids are released simultaneously for M. persicae control. In this work, we evaluated the oviposition site selection and prey preference of predatory gall midges or parasitoids in the presence of intragroup species, and the efficiency of aphid control in greenhouse greenhouses after releasing them in various methods. Predatory gall midge will avoid laying eggs on plants with only parasitic aphids, but A. gifuensis has no obvious parasitism options under predatory gall midge larval activity. Intraguild predation has no significant effect on predation preference in A. aphidimyza , but significantly alters parasitism preference in A. gifuensis . In addition, among all treatments in the greenhouse experiment, the best aphid control was achieved by releasing A. aphidimyza for 8 days followed by the A. gifuensis treatment, while the treatment of releasing A. gifuensis for 8 days followed by A. aphidimyza was less effective in controlling aphids than the treatment of releasing only A. aphidimyza . These results suggest that simultaneous release of A. gifuensis and A. aphidimyza for peach aphid control is synergistic, but is significantly affected by the mode of release. It may prove valuable for the development improved augmentative release strategies for these two natural enemies.