Weed-Insect Interactions in Annual Cropping Systems

Agricultural production is increasingly viewed as more than a source of food, feed, fiber and fuel, but also as a system of interdependent biotic and abiotic components that interact to produce ecosystem services and disservices. Weeds and insects are commonly viewed as non-desirable components of agroecosystems that should be managed. However, weeds can also provide benefits to cropping systems, such as providing resources and habitat to pollinators and other beneficial arthropods. This review on weed-insect interactions in annual cropping systems focuses on functional interactions within the context of regulating and supporting ecosystem services and disservices. Regulating services are those that act as regulators of the environment, such as weed-insect interactions that contribute to the regulating services of pollination and biological control, but also contribute to the disservices of crop and cover crop seed predation, and maintenance of insect pests and insect-transmitted phytopathogens. Supporting services include habitat and biodiversity that are necessary for the production and maintenance of the other types of ecosystem services. Here we review the impacts of weed-insect interactions as a component of biodiversity. We conclude by identifying some knowledge gaps that hinder our understanding of trade-offs when seeking to improve net positive ecosystem services in annual cropping systems.