A female sex pheromone in Bruchidius atrolineatus (Pic) (Coleoptera, Bruchidae): analysis of the factors affecting production or emission of this pheromone

ABSTRACT. . The females of the tropical Bruchid Bruchidius atrolineatus (Pic) (Coleoptera) produce a sex pheromone that influences male behaviour. This pheromone, tested on males in an olfactometer, triggers characteristic antennal movements followed by a distinct chemo-anemotaxis. Sex pheromone production depends on the age of the females and is partly correlated with their ovarian activity. Females 0–24 h old are not attractive, but they begin to attract males on the second day of adult life. Vitellogenesis seems to correlate with the emission or the production of the pheromone but there is no precise synchrony between the two phenomena which are probably induced by the same endocrine factors. Within 1 h after mating there is a decrease in the females' attractiveness, which lasts at least 48 h. Under our experimental conditions no particular rhythm of production or emission of the sex pheromone in B. atrolineatus could be observed.