Cowpea, Vigna unguiculata (L.) Walp., is susceptible to a wide spectrum of insect pests from seedling to harvest as well as in storage. Insecticide use has been the most commonly adopted method for the control of cowpea pests. However, due to the deleterious effects of insecticides on man, livestock and the environment, research over the years has been focused mainly on developing resistant/tolerant cultivars as a vital component in the integrated management of cowpea pests. This approach has, however, recorded varying degrees of success, due in part to the multiple and often overlapping pest complex attacking at different phenological growth stages of the crop.

In spite of the progress in the utilisation of insect-resistant cowpea varieties, the use of resistance as a control tactic has by no means been fully realised. There are many important cowpea insect pests for which resistant varieties are not yet available for commercial cultivation. Where resistant varieties are available for a given insect, these varieties may not be widely planted because of their unsuitability to local conditions.

In this paper, the status of host plant resistance research in cowpea is reviewed and some novel approaches aimed at solving its seemingly intractable pest problem are proposed, based on the state-of-the-art scientific and crop biotechnological development. The proposed framework for orientation of cowpea resistance research should ensure yield stability and sustainability for the resource-poor, smallscale farmers in Africa.

Crop losses caused by pests are a major problem in both developed and developing countries. Increasing awareness of the environmental consequences of indiscriminate use of chemical pesticides has provided new impetus for the search for alternative ways of managing pests. Particular emphasis has been placed on strategies that cause less pollution to the environment and those that are affordable, especially for the less developed countries. One concept that has received a lot of attention is integrated pest management (IPM), which seeks to manage pests and minimise crop losses by using methods that are economically viable and less harmful to the environment.

At least three distinct classes of new biotechnologies can have impacts on integrated pest management. These include microbial biotechnologies, plant molecular biology and genetics, and insect molecular biology and genetics. For example, recent advances in molecular biology have enabled scientists to overcome species barriers and to genetically alter plants, animals and microorganisms in ways that were not possible before. Already, several genetically altered plants which express genes that confer protection against pests have been produced. The techniques of biotechnology have also played important roles in elucidating pest populations and in studying the population dynamics of biological control agents and other types of organisms that live in association with crop plants. This article examines some of the major developments in the areas of molecular biology, genetics and biotechnology and the potential impacts that they could have on integrated pest management worldwide.

The potential of plant genetics in the overall context of integrated pest control could be viewed simply as the potential of plant resistance in pest management. Genetic resistance in plants is one of the most effective and economic means of controlling plant pests. Resistant plants are the first line defence against pests. Successes in breeding for pest resistance depend upon the sound knowledge of the plant genes controlling resistance to pests.

Recent report on the existence of two nonatlelic and independent genes, Rac1 and Rac2 in cowpea cultivars ICV 10 and TVu 310, and ICV 11 and ICV 12, respectively, from the ICIPE has broadened the scope of cowpea breeding against aphid biotypes. Use of biotechnology as a plant breeding tool in transferring resistance genes into agronomically suitable cultivars appears to hold good promise for the future.