The Biological Control of Cassava Mealybug in Africa

Cassava, brought from South America 300 years ago free of its pests, became a major subsistence crop in Africa. A mealybug was mistakenly introduced in the early 1970s. By the 1980s the mealybug was a major pest. The International Institute of Tropical Agriculture found a parasitic wasp in South America and reared and released it in Africa. Conservatively estimated, the benefit-cost ratio for this program is 149 to 1. This success indicates that biological control can play an important role in pest management.