SEX-PHEROMONE PRODUCTION IN CALLOSOBRUCHUS-MACULATUS (COLEOPTERA, BRUCHIDAE) - ELECTROANTENNOGRAPHIC AND BEHAVIORAL-RESPONSES

Behavioral and electroantennogram (EAG) assays were used to determine rhythmicity and dynamics of the sex pheromone biology of the bruchid b eetle, Callosobruchus maculatus (F,), Beetles were sexually active thr oughout the photophase. Virgin females entrained to a 16:8 L:D light c ycle emitted more sex pheromone during the first half of photophase th an during the second half of photophase or during scotophase. Sex pher omone production increased from day 0 to day 3 of adult life, and then decreased as females grew older, Availability of garbonzo beans, one of the larval food and adult oviposition hosts, to females did not sti mulate sex pheromone production. Mating resulted in a reduction in pos t-coital sex pheromone production. Mated females, however, regained at tractiveness to males and this attractiveness increased from day 1 to day 3 after first mating when females had been mated at day 0 after em ergence. (Z)-3-Methyl-2-heptenoic acid (Z32A) and (Z)-3-methyl-3-hepte noic acid (Z33A), two compounds implicated as sex pheromone components for C. maculatus, both elicited male EAG and behavioral responses in the beetles; however, Z33A elicited larger responses than Z32A. Binary mixtures of the two compounds were more effective than either compoun d alone. Copyright (C) 1996 Elsevier Science Ltd