IPM for food storage in developing countries: 20th Century aspirations for the 21st Century

In tropical developing countries, especially in humid zones, pest infestation in stored food is inevitable. In the past, the focus of tropical storage pest management was on adapting pest control techniques with contact insecticides and fumigants that had proved effective in industrialized countries. Three decades ago it was still widely assumed that these techniques would continue to provide a panacea for the foreseeable future. At the end of the century, the reality is very different: widespread resistance; non-efficacy of surface treatments; no ‘fifth generation’ of pesticides; narrow choice of fumigants; and consumer demand for minimal or zero residues. In response, research on biorational alternatives has increased in recent years, especially on ‘additives’. By contrast, research on ecologically-based alternatives has stagnated. Studies of the synecology of storage pest communities remain very rare. Few authors have addressed the particular problems of IPM decision-making in storage, and in practice the emphasis is on pragmatic mixtures of control methods rather than a calculated application of optimum procedures in response to monitoring and risk assessment. At the end of the 20th Century, IPM in food stores is still an aspiration rather than a reality, and we still have much to learn about the ecology and behaviour of pests in the post-harvest system if we are to achieve an IPM approach to storage pests in the 21st Century.