Economics of biological control of cassava mealybug in Africa

Pest populations of the cassava mealybug Phenacoccus manihoti Mat.-Ferr. (H omoptera: Pseudococcidae) were reduced successfully by the biological contr ol agent Apoanagyrus (Epidinocarsis) lopezi De Santis (Hymenoptera: Encyrti dae) throughout most of sub-Saharan Africa. The economics of the project we re evaluated based on data from field trials, socio-economic surveys, publi shed results, and financial information provided by the International Insti tute of Tropical Agriculture (IITA) and the national programmes. Costs and benefits for the biological control of P. manihoti were calculated over 40 years (1974-2013) for 27 African countries, for four different scenarios, t aking into account that impact by A. lopezi and speed of the impact differ between ecological zones. A reasonable calculation considering compounded i nterest resulted in a benefit cost ratio of about 200 when cassava was cost ed at world market prices, and of about 370-740 when inter-African prices w ere considered. (C) 2001 Elsevier Science B.V. All rights reserved.