CHEMICAL BASIS OF DIFFERENTIAL OVIPOSITION BY LEPIDOPTEROUS INSECTS

Phytochemical mediators serving as attractants, repellents, stimulants, or deterrents in oviposition behavior of moths and butterflies are reviewed in regard to the chemical mechanism of host selection. Ovipositing females seem generally to utilize plant volatiles as cues for orientation to host plants, and the subsequent contact evaluation of plants by means of less- or non-volatile secondary metabolites is usually of great significance in host recognition. Most lepidopterans appear to be induced to oviposit in response to a single host-specific compound, while extreme synergism of multiple components features the stimulatory system of oviposition enacted by some butterflies. Recent investigations clearly demonstrate that acceptance or rejection of a particular plant by females is regulated not only by the presence or absence of oviposition stimulants but by negative stimuli evoked by co-occurring deterrents. The epideictic pheromones implicated in host assessment by females are also referred to in this review. (C) 1995 Wiley-Liss, Inc.