PII: S0738-0593(01)00035-9

Abstract

The Tropical Whitefly IPM Project (TWFP) is an initiative of the Systemwide IPM Programme of the Consultative Group on International Agricultural Research (CGIAR), financed by the Department for International Development (DFID) of the United Kingdom, the Danish International Development Agency (DANIDA), the United States Department of Agriculture (USDA) and Agency for International Development (USAID), the Australian Centre for International Agricultural Research (ACIAR), and the New Zealand Agency for International Development (NZAID), to manage whitefly pests and whitefly‐transmitted viruses in the Tropics. Participating CGIAR and other international centers include the Centre for International Tropical Agriculture (CIAT); the International Institute of Tropical Agriculture (IITA); The International Potato Centre (CIP); the Asian Vegetable Research and Development Centre (AVRDC); and the International Centre of Insect Physiology and Ecology (ICIPE), in close collaboration with the National Resources Institute (NRI‐UK); national agricultural research institutions; agricultural universities; and advanced agricultural research laboratories in Africa, Asia, Europe, the Pacific Region, and the Americas. The TWFP was launched in 1996 as five separate but closely linked subprojects targeting: (1) Bemisia tabaci as a vector of viruses affecting cassava and sweet potato in sub‐Saharan Africa (IITA, NRI, CIP, CIAT); (2) B. tabaci as a vector of viruses in mixed cropping systems of Mexico, Central America, and the Caribbean (CIAT); (3) B. tabaci as a vector of viruses in mixed cropping systems of eastern and southern Africa (ICIPE, AVRDC); (4) B. tabaci as a vector of viruses in mixed cropping systems of Southeast Asia (AVRDC); (5) Trialeurodes vaporariorum as a pest in mixed cropping systems of the Andean highlands (CIAT); and (6) whiteflies as pests of cassava in South America (CIAT). Diagnostic surveys conducted in Phase I (1997–2000) clearly showed that the two main whitefly pests in the Tropics are B. tabaci and, in the highlands, T. vaporariorum. Other whitefly species investigated by the TWFP included B. afer and Aleurotrachelus socialis. B. tabaci is the main vector of plant viruses inducing African cassava mosaic disease, sweet potato virus disease, bean golden mosaic disease, and many other diseases of horticultural crops, mainly tomato, hot and sweet peppers, squash, melon, and several other cucurbits. Genetic resistance was identified as the most important component of an IPM programme, followed by phytosanitary, cultural and legal measures. The two most important factors contributing to whitefly/virus epidemics were shown to be pesticide abuse and the use of virus‐infected planting materials. Biological control is only effective in cropping systems with minimal or rational use of insecticides, and should be considered only as a complementary IPM strategy. Farmer education and technical assistance are considered the most critical steps toward the implementation of sustainable and economically viable IPM strategies in tropical countries affected by whitefly pests and whitefly‐transmitted viruses.