EFFECTS OF PLANT EPICUTICULAR LIPIDS ON INSECT HERBIVORES

The primary role of epicuticular lipids on aerial plant surfaces is pr evention of water loss, but their species-specific chemical compositio n and their variable crystal morphology suggest other ecological funct ions. Among these functions is mediation of interactions between plant s and insect herbivores. Epicuticular lipid extracts and individual li pid components enhance or deter oviposition, movement, and feeding. Th e physical structure of plant surface lipids can affect insect herbivo re attachment and locomotion. Surface lipids may also affect herbivore s indirectly by influencing predatory and parasitic insects. Glossy cr op phenotypes are often less susceptible to insect herbivores than are normal phenotypes. The epicuticular lipids of glossy plants are usual ly reduced in amount and have dramatically different chemical composit ion and morphology. Study of the basis of the reduced susceptibility o f glossy plants can help elucidate the role of plant surface lipids in insect-plant interactions.