Pheromone Perception in Lepidoptera

Abstract

The sex pheromone of many lepidopteran species has been identified as a mixture of 2–4 components. Even the first identified pheromone, bombykol, in Bombyx mori silkworms (Butenandt et al. 1959) has recently been found to involve a second component, bombykal (Kasang et al. 1978). If a single pheromone component is used, it is assumed that the sequence of evoked behavioral responses is elicited by it, along with any visual, tactile, or auditory stimuli that may operate at close range. With multichemical pheromone systems, however, it has been found (Carde et al. 1975; Baker et al. 1976) that some of the components, named primary components (Roelofs and Carde 1976), elicit long-distance upwind anemotaxis, whereas other components named secondary components, are not essential for eliciting upwind anemotaxis, but are used in combination with the primary components to evoke close-range responses, such as landing, wing fanning, hair pencilling, and copulatory attempts. For example, the redbanded leafroller moth, Argyrotaenia velutinana, has a 3-component sex pheromone system consisting of (Z)- and (E)-ll-tetradecenyl acetate (91:9) (Zll- and Ell-14:Ac) and dodecyl acetate (Roelofs et al. 1975). The long-range upwind anemotactic responses of the males are elicited by the geometrical isomers, whereas, the presence of dodecyl acetate in combination with the isomers elicits an increase in the frequency of landing, walking to the source while wing fanning, and finally copulatory attempts (Baker et al. 1976).