Artificial selection of zoophagous lines of the biological control agent Dicyphus hesperus

Abstract

Zoophytophagous predators can be beneficial for controlling crop pests in greenhouses. Yet, they can also cause significant economic damage. More zoophagous and effective predator lines can be developed by selectively breeding highly zoophagous individuals. Hence, artificial selection based on the degree of zoophagy in zoophytophagous predators can improve their efficiency as biocontrol agents while reducing the risk of crop damage. However, artificial selection on zoophagy could cause changes in other behavioral or life history traits due to genetic correlation or pleiotropy. These changes can affect the ecological conditions in which biological control agents work. We created highly and lowly zoophagous lines of Dicyphus hesperus Knight (Hemiptera: Miridae) using artificial selection. We tested genetic correlations between zoophagy and food patch exploitation equity in four generations of artificial selection. The results revealed that females were more zoophagous than males. The broad sense heritability (H²) of zoophagy was 0.38 in females and 0.29 in males. Artificial selection on zoophagy led to decreased food patch exploitation equity, yet the traits were not genetically correlated. Our results suggest that artificial selection can be used to develop lines of D. hesperus that enhance the benefits of biological control and modify ecological factors such as prey density and distribution.