Male accessory gland factors increased sex pheromone titres in the glands ofSpodoptera liturafemale moths by inhibiting calling behavior

Abstract

14Moths are the most widely studied example of pheromones in animals. However, 15 little is known about the mechanism of intrasexual and mating-related intersexual 16 regulation of pheromone production and release in female moths. Our previous 17 studies in Spodoptera litura found that mating induced a higher sex pheromone titre in 18 the pheromone gland (PG) and mating or male accessory gland (MAG) extract 19 suppressed female calling behavior. We therefore hypothesize that the inhibition of 20 female calling behavior by mating or MAG factors likely suppresses the release of sex 21 pheromones and thus results in a higher pheromone titre in the PG. To test this 22 hypothesis, in the present study, we introduced an artificial calling behavior 23 suppression treatment by gently knocking on and shaking the testing boxes contained 24 moths once every 10 minutes. Results show that this treatment significantly increased 25 pheromone titres in virgin or saline injected virgin females, and the increase rates are 26 similar to those of mating and MAG extract treated ones. These results have 27 suggested that the increase of sex pheromone titer in the female PG after mating in S. 28 litura is due to the inhibition of female calling behavior by MAG factors. Moreover, 29 results of this study also suggest that female calling behavior is positively correlated 30 to pheromone release and likewise, the calling behavior and sex pheromone release in 31 S. litura females are directly under the neural control, and modulated by molecular 32 and environmental factors. 33 34

Receptivity and Remating Propensity in Female Spodoptera litura (Fabricius) after Mating with an Irradiated Male or Its F1 Male Progeny

“…Lu et al (2017) showed that mating resulted in a higher sex pheromone titer in the pheromone gland (PG) of S. litura [51]. Later, Xu et al (2019) attributed the suppression of female calling behavior to mating and MAG factors, which resulted in higher sex pheromone titers in mated S. litura females, presumably due to a lower release of pheromones [78]. This implied that irradiation probably influenced MAG factors that might have consequently failed to suppress female calling behavior effectively when mated to F 1 males due to insufficient or less effective ejaculate.…”