Refuges as a predictor of parasitoid diversity.

A central problem in ecology is predicting the diversity of communities. Insect parasitoids may encompass 20 percent of all insect species; hence, establishing the mechanisms that drive parasitoid species richness represents a major step in understanding the diversity of terrestrial communities. An assemblage model, based on population dynamic constructs, shows how the presence of refuges from parasitoid attack can generate diversity patterns that are in good accord with global data on structural protection from parasitism resulting from host feeding biology. This theory offers a simple ecological explanation for the range of diversities observed in real parasitoid assemblages. Predicting parasitoid diversity may be a realistic goal, at least for those systems in which the basic demography is well understood.