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ensure accuracy. Conserving Biodiversity: A Research Agenda for
Development Agencies being devastated by a psyllid insect pest.
Similarly, the monocultures of cassava in West and Central
Africa were ravaged when the cassava mealybug was inadvertently
introduced from South America, the original home of cassava. The
mealybug was brought under control only through the introduction
of a natural parasitic wasp—a move that may have been worth
billions of dollars and illustrates the importance of
understanding the role of biodiversity in agroecosystem
management (Norgaard, 1988; Neuenschwander et al., 1990). As the
resource depletion model of development has been adopted
worldwide, the loss of biological diversity has accelerated.
Ultimate socioeconomic reasons for this loss include the failure
to consider environmental externalities in