Plant chemicals that affect the sexual behavior of Anastrepha fraterculus males

SEGURA D.; BACHMANN, GUILLERMO E.; BELLIARD, SILVINA A.; RUIZ, M. J; JUAREZ, MARIA LAURA; FERNÁNDEZ, PATRICIA C.; CLADERA, J.L.; SHELLY, TODD E; VERA M. T.

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

Background. Insect-plant interactions are often mediated by chemical compoundsproduced by the plant that may affect insects in positive or negative ways. Plant secondarymetabolites affect the sexual behavior and sexual communication of insects in variousways: acting as cues to ?rendezvous? sites for mating; stimulating signaling behavior; ormaking pheromones more attractive to the opposite sex. Here, we evaluated the effect ofphytochemicals produced by guava fruit on the mating behavior and reproductive biologyof Anastrepha fraterculus.Methods: Wild as well as laboratory males were exposed to the aroma of guava fruit andthen evaluated in terms of mating success, latency to mate, mating duration, callingbehavior, pheromone emission rate and cuticular chemical profile. Experiments werecarried out under laboratory conditions.Results: Exposed males achieved significantly more matings than non-exposed malesirrespective to male origin. Latency to mate was not affected by exposure to guava, butexposed males mated for longer periods of time than non-exposed males. Guava exposureincreased the signaling rate by 30-40% (measured through wing fanning and salivarygland exposure) when comparing exposed and non-exposed males, both for laboratoryand wild flies. Enhanced signaling was accompanied by larger amounts of sex pheromonebeing released by exposed males, at least for three (anastrephin, epianastrephin,suspensolide) of the four compounds that were quantified. However, no differences werefound 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 towardscuticle extracts from exposed and non-exposed males. Females mated with guava exposedmales showed higher fecundity than females mated to non-exposed males, while fertilitydid 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 malecuticle. Females would obtain a direct benefit from choosing exposed males in terms ofrealized fecundity.