Biological control within IPM systems with GM plants
Abstract: A range of currently available and close-to-the-market GM crops were examined for their potential contribution to biological control and integrated pest management. Most GM crops and their new traits have the potential to improve crop production especially under heavy pest, disease and weed pressure. In particular insecticidal and virus-resistant crops can help to keep pests and diseases in check, to lower the chemical pesticide load in the environment, and to support complementary IPM tactics such as the active use of biocontrol agents, and increased reliance on natural control. The agroecological benefits of herbicide-tolerant crops remain more controversial, as no clear decrease of pesticide inputs can be demonstrated. Intensified simplification of the agroecosystem hampers ecosystem services such as biocontrol and pollination. The theoretical benefits to IPM of pest and disease resistant GM-crops seldom seem to be realized in a sustainable way in reality: GM-crops usually are seen by the growers as a stand-alone technology without any real attempt to integrate them as a component in integrated pest management. This leads to short-term, unsustainable agroecological benefits, and eventual loss of these benefits as has been observed in parts of the USA by the return of the growers to conventional maize varieties.Similarly, mechanical weeding is increasingly needed in HT-GM cotton. Thus, the ”reality gap” appears to erode the contribution of GM-crops to IPM, and results in the wastage of rare opportunities to increase the sustainability of our food production by short-sighted production strategies.