Fruit availability influences the seasonal abundance of invasive stink bugs in ornamental tree nurseries

Abstract

Invasive plant-feeding insects cause billions of dollars in economics losses annually around the world. Understanding how they utilize different host plants directly informs their management. The highly invasive brown marmorated stink bug, Halyomorpha halys (Stal) (Hemiptera: Pentatomidae), has destroyed crops and invaded homes since its discovery in the U.S. in the mid-1990s. In this study, we test the hypothesis that in diverse resource environments, the presence and maturity of fruits on trees influences the abundance of H. halys. Observational surveys of the abundance of H. halys life stages (egg masses, nymphs, and adults) on 3884 trees of 223 cultivars in woody plant nurseries revealed that fruit maturity was a strong predictor of the seasonal abundance and within-tree distribution of H. halys. We next explicitly tested whether fruits themselves were the key resource for H. halys through a manipulative field experiment. Removal of fruits from trees suppressed stink bug abundance throughout the season. Despite being considered a broad feeding generalist, our results highlight that in landscapes with highly heterogeneous and ephemeral resources, H. halys specializes on finding mature fruits. Therefore, H. halys can be controlled by designing landscapes with fruitless varieties of popular trees, exploiting phenological mismatches between the pest and its host plants, and through targeted management of H. halys on fruiting trees in the landscape.