Evidence for a female sex pheromone in the brassica pod midge Dasineura brassicae

Abstract

ABSTRACT. The responses of Dasineura brassicae Winn. (Diptera, Cecidomyiidae) to odours from both male and female midges and from their host (Brassica napus) and non‐host (Vicia faba) plants were studied using a Y‐tube olfactometer. Female but not male D. brassicae are attracted to crushed B. napus leaves but not to those of V. faba. Males are attracted to live virgin females, to crushed virgin and mated females and to hexane washes of females, suggesting that the female produces a sex pheromone that attracts males. Males were also attracted to hexane washes of female ovipositors, but not to washes of the bodies of females without ovipositors, suggesting that the ovipositor is the site of pheromone release or production. Males were not attracted to live mated females or to other live or crushed males and mated females were not attracted to other mated females.