OVARIAN DEVELOPMENT PHEROMONE PRODUCTION AND MATING IN EYE GNAT HIPPELATES COLLUSOR

Mating in female eye gnats is correlated with the degree of ovarian development which is utilized as a physiological age indicator. Mating occurred in females having egg development of stages 6 to 9. Females at stage 7 mated more frequently than females at the other stages of ovarian development when the males were given a choice of different aged females. Live females with ovaries in stages 6 to 9 produced a sex attractant and females at stage 10 produced a repellent. Females with stages 2 to 4 ovaries did not attract males. Ether extracts from females with stages 6 to 9 ovaries attracted males, extracts from females with mature eggs repelled males, and extracts from females with stage 2 ovaries did not attract males. Attractancy was only detectable in laboratory olfactometer tests. Field tests on female extracts did not attract males in the field. The sex attractant produced by female eye gnats probably acts as a sex recognition scent. © 1968.