Semi-natural Habitats Support Populations of Stink Bug Pests in Agricultural Landscapes

Semi-natural habitats are considered fundamental for biodiversity conservation and the provision of biological control services in agroecosystems. However, crop pests that exploit different types of habitats during their life cycle might thrive in complex landscapes. Understanding how crop pests use a range of resources across the agroecosystem is fundamental to plan sustainable crop protection strategies. Here we explored the effects of local habitat type (i.e., annual crop, perennial crop, dry grassland and forest) and landscape composition (increasing cover of forest and dry grassland) on stink bug pests in Mediterranean agroecosystems. Stink bugs (Hemiptera: Pentatomoidea) are polyphagous and highly mobile organisms considered a serious threat for numerous crops worldwide. To better understand how stink bugs used different habitats, we sampled active adults and juveniles in spring and summer, and overwintering individuals in autumn and winter. Our results showed that semi-natural habitats supported more abundant stink bug populations, potentially providing alternative feeding, reproduction, and overwintering sites. Specifically, we found more active adults and juveniles in dry grasslands, while forests hosted greater numbers of overwintering individuals. Moreover, forest cover in the landscape was positively related to active stink bug abundance in all sampled habitats. Finally, we found complex landscapes rich in overall semi-natural habitats to support higher abundance of overwintering individuals in both forests and dry grasslands, while perennial crop might provide suitable overwintering sites in highly simplified landscape. These results have important implications for pest management as crop fields situated in complex landscapes might be more susceptible to pest infestation. Effective control strategies may require a landscape-based approach.