ABSTRACT
The cassava mealybug (CM) Phenacoccus manihoti Matile-Ferrero was accidentally introduced into Africa in the early 1970s, and it subsequently spread over most of the continent. Surveys of subsistence farms, exclusion experiments, and a computer simulation model have all documented the efficiency of E. lopezi in preventing CM outbreaks. Rearing of E. lopezi started when the scientific description of the species was the only available information about this insect. Systems of different technological levels have been developed for the soilless mass rearing of CM and its natural enemies. The impact of a biological control project through inoculative releases, such as the one with E. lopezi, is usually evaluated on the basis of the project costs and the savings incurred to the farmer. Cost estimates are, however, difficult to obtain because rearing was done in old, refurbished buildings and building costs, as well as salaries, were paid in non-convertible local currency.
