Improving the establishment of Orius laevigatus through optimized supplemental diets and multi-trait selected strains

Abstract: Supplementary foods are widely used in augmentative biological control programs
to enhance the establishment and persistence of natural enemies in crops. Previously, we
developed a supplemental diet based on three astigmatid mite species that significantly
improved the establishment of phytoseiids, mirids, and anthocorids. This feeding strategy
successfully enhanced the establishment of Orius laevigatus in pollen-deficient crops such as
cucumber, as well as in crops that are not yet flowering at the time of predator release, including chrysanthemum and other ornamental plants. Concurrently, we developed new strains of O. laevigatus with improved biological and functional traits. Five strains were selected for resistance to different pesticide active ingredients. Additional strains were selected for improved performance on pollen-based diets, enhanced survival and development at low temperatures, and superior performance when fed supplemental diets based on astigmatid prey mites. In the present project, we further improved these lines by combining previously selected traits to obtain multi-trait strains exhibiting resistance to multiple active ingredients and enhanced crop establishment capacity. The performance of these improved strains was evaluated in various greenhouse vegetable and ornamental crops, in combination with optimized supplemental feeding strategies. Our results demonstrate the potential of integrating nutritional and genetic improvement approaches to strengthen the reliability and resilience of augmentative biological control programs.