Plant chemicals that affect the sexual behavior of Anastrepha fraterculus males

SEGURA, D.; BACHMANN, G. E.; BELLIARD S.; RUIZ M. J.; JUÁREZ M. L.; FERNÁNDEZ, P.; CLADERA, J.; SHELLY T. ; VERA M. T.

Congreso; 10th International Symposium on Fruit Flies of Economic Importance; 2018

Background. Insect-plant interactions are often mediated by chemical compounds produced by the plant that may affect insects in positive or negative ways. Plant secondary metabolites affect the sexual behavior and sexual communication of insects in various ways: acting as cues to ?rendezvous? sites for mating; stimulating signaling behavior; or making pheromones more attractive to the opposite sex. Here, we evaluated the effect of phytochemicals produced by guava fruit on the mating behavior and reproductive biology of Anastrepha fraterculus. Methods: Wild as well as laboratory males were exposed to the aroma of guava fruit and then evaluated in terms of mating success, latency to mate, mating duration, calling behavior, pheromone emission rate and cuticular chemical profile. Experiments were carried out under laboratory conditions. Results: Exposed males achieved significantly more matings than non-exposed males irrespective to male origin. Latency to mate was not affected by exposure to guava, but exposed males mated for longer periods of time than non-exposed males. Guava exposure increased the signaling rate by 30-40% (measured through wing fanning and salivary gland exposure) when comparing exposed and non-exposed males, both for laboratory and wild flies. Enhanced signaling was accompanied by larger amounts of sex pheromone being released by exposed males, at least for three (anastrephin, epianastrephin, suspensolide) of the four compounds that were quantified. However, no differences were found in the chemical profile of the cuticle of guava exposed and non-exposed males. Furthermore, EAG studies showed that females have the exact same response towards cuticle extracts from exposed and non-exposed males. Females mated with guava exposed males showed higher fecundity than females mated to non-exposed males, while fertility did not differ. Conclusions: Exposure to guava enhanced male mating success and signaling rate in A. fraterculus. The effect does not seem to be mediated by a change in the aroma of the male cuticle. Females would obtain a direct benefit from choosing exposed males in terms of realized fecundity.