From Integrated to System-Wide Pest Management: Challenges for Sustainable Agriculture

Insect pests and vectors of animal and plant diseases are a major constraint to the improvement of agricultural productivity, and a continuous threat to food security and livelihoods, particularly in less developed countries. The excessive reliance on broad-spectrum insecticides as the prevailing strategy to control pest outbreaks for over 50 years worldwide has showed some limitations with the increasing number of documented cases of field-evolved resistance and re-emergence of pests or vector-borne diseases that had been previously placed under control. More widely, agriculture intensification has contributed to the erosion of crop and livestock genetic diversity and fragmentation or suppression of natural habitats supporting biodiversity-mediated ecosystem services such as insect pest regulation. These concerns are being exacerbated in a context of global change, including population growth, global warming, transboundary trade, on-farm loss of biodiversity, and societal demand for a safer environment and residue-free food, which foster increasingly stringent pesticide use in agriculture and livestock farming. Integrated pest management (IPM) is an ecosystem approach to crop production and protection that combines different management strategies and practices to grow healthy crops and minimize the use of pesticides. IPM thus requires science-based knowledge of the life cycle of pests and their interactions with the environment, including natural enemies and habitats. Field realities, however, show that IPM is often used in a reactive manner and at a local scale, as a simple toolbox. A fundamental shift to a system-wide approach is needed to achieve preventive and effective pest control, while enhancing crop yields, and reducing farmers' reliance on pesticide use and the associated environmental impacts. This shift should at least consider: (i) the functional area of the target pest populations; (ii) the complexity of ecological processes driving regulation; and (iii) the intelligent combination of pest control technologies. Area-wide integrated pest management is a promising way to improve conventional pest control by targeting pest populations within their functional area. This approach requires a better knowledge of target pests, especially regarding their life system (spatial distribution, habitats, dispersal ability over time and space, genetic structure, metapopulation dynamics and gene flow), ecological processes driving regulation (food web networks and natural enemy assemblages), and responses to farming practices at a field and landscape scale. In addition, the success of such an approach relies on a strong cooperation amongst stakeholders for the design, implementation and compliance of pest management programs, and requires farmer education and external coordination, either from governmental bodies or farmers associations.