Submitted to: Crop Protection
Publication Type: Peer reviewed journal
Publication Acceptance Date: 6/1/2009
Publication Date: 12/1/2009
Citation: Lundgren, J.G., Gassmann, A., Bernal, J., Duan, J.J., Ruberson, J. 2009. Ecological Compatibility of GM Crops and Biological Control. Crop Protection. 28(12):1017-1030. Interpretive Summary: GM crops (both insect resistant and herbicide tolerant types) and biological control are two important aspects of pest management. Their compatibility relies both on toxicological effects of GM crops to natural enemies (predators, parasitoids, and insect pathogens), and on how GM crops alter the environment in which natural enemies live. Specifically, GM crops sometimes affect both the quantity and quality of prey and non-prey foods, and alter the habitat quality of cropland for beneficial natural enemies. We discuss the types of studies that are conducted to assess the compatibility of GM crops and biological control, the ways in which natural enemies interact with GM crops, and discuss the current literature on the effects of GM crops on biological control agents. Recognizing the strengths and weaknesses illustrate ways that these two pest management practices can work together within integrated pest management systems. Three specific examples are illustrated where 1) biological control can affect pest resistance to GM crops, 2) biological control can act against herbivores that aren’t targeted by the GM crop, and 3) herbicide tolerant crops can provide flexibility to growers in how they manage their farmland, and provide opportunities for managing cropland in ways that promote integrated pest management with biological control.
Technical Abstract: Insect-resistant and herbicide-tolerant genetically modified (GM) crops pervade many modern cropping systems, and present challenges and opportunities for developing biologically-based pest management programs. Interactions between biological control agents (insect predators, parasitoids, and pathogens) and GM crops exceed simple toxicological relationships, a priority for assessing risk of GM crops to non-target species. This synthesis prioritizes understanding the bi-trophic and prey/host-mediated ecological pathways through which natural enemies interact within cropland communities, and how GM crops alter the agroecosystems in which natural enemies live as means for determining the compatibility of these two technologies within integrated pest management systems. Insect-resistant crops can affect the quantity and quality of non-prey foods for natural enemies, as well as the availability and quality of both target and non-target pests that serve as prey/hosts. When they are used to locally eradicate weeds, herbicide-tolerant crops alter the agricultural landscape by reducing and changing the remaining vegetational diversity. This vegetational diversity is fundamental to biological control when it serves as a source of habitat and nutritional resources. Some inherent qualities of both biological control and GM crops provide opportunities to improve upon sustainable IPM systems. For example, biological control agents may delay the evolution of pest resistance to GM crops, and suppress outbreaks of secondary pests not targeted by GM plants, while herbicide-tolerant crops facilitate within-field management of vegetational diversity that can enhance the efficacy of biological control agents. By examining the ecological compatibility of biological control and GM crops, and employing them within an IPM framework, the sustainability and profitability of farming may be improved.