ABSTRACT
Microorganisms associated with plants are generally diverse and abundant (Dickenson and Preece, 1976; Blakeman, 1981; Wicklow and Carroll, 1981; Fokkema and van den Hueval, 1986; Andrews and Minao, 1991; Bills and Polishook, 1991). Despite this, entomologists studying ecological interactions between plants and insect herbivores have until recently overlooked the potential influence of microbes (Price et al., 1986; Letourneau, 1988; Berenbaum, 1988; Marquis and Alexander, 1992). Only recently has the role of microbes in modulating plant-insect interactions been addressed empirically. For example, fungi may indirectly affect seed mortality in shrub-steppe communities through reducing predation by granivores of fungal-infested seeds (Crist and Friese, 1993). Microorganisms likely mediate interactions between insect herbivores and plants in diverse ways (Hatcher, 1995; Barbosa et al., 1991).
