Effect of Fruit Volatiles from Native Host Plants on the Sexual Performance of Anastrepha fraterculus sp. 1 Males

SIMPLE SUMMARY: The South American fruit fly, Anastrepha fraterculus, is an important fruit pest. Males of this species are sexually stimulated by odors released by one of their main hosts, Psidium guajava (guava) fruit. Stimulated males release more pheromone and perform sexual displays more frequently than males that did not perceive fruit odors. This phenomenon was documented only for guava, a native host, whereas odors from other, exotic host species, such as mango, grapefruit and orange, do not trigger any stimulation in males. This might indicate that the male response is only triggered by native hosts, with which they have a common evolutionary history. Here we studied the effect of odors released by fruits of other four native host species of A. fraterculus sp. 1, namely Eugenia myrcianthes, Juglans australis, Psidium cattleianum, and Acca sellowiana, using guava as a positive control. Sexual displays and mating success were only affected by guava (as expected) and P. cattleianum. Interestingly, the two species belong to the same plant genus, which suggests a strong evolutionary relationship between A. fraterculus sp. 1 and, possibly plants of this genus. The present findings could help improving the sterile insect technique, an efficient pest control method widely used against fruit flies. ABSTRACT: Anastrepha fraterculus sp.1 males are sexually stimulated by the aroma of fruit of its native host Psidium guajava (guava). Other hosts, which are exotic to A. fraterculus, do not enhance male sexual behavior. Here we evaluate the effects of fruit volatile exposure on male A. fraterculus sp. 1 sexual performance using other native hosts, under the hypothesis that male improvement derives from a common evolutionary history between A. fraterculus sp. 1 and its native hosts. Four species were evaluated: Eugenia myrcianthes, Juglans australis, Psidium cattleianum, and Acca sellowiana. Guava was used as a positive control. Males were exposed to fruit from 12:00 pm to 4:00 pm, from day 8 to day 11 post-emergence. On day 12, we evaluated their calling behavior and mating success. Both guava and P. cattleianum enhanced calling behavior. Mating success was enhanced only by guava and a trend was found for P. cattleianum. Interestingly, the two hosts belong to the Psidium genus. A volatile analysis is planned to identify the compounds responsible for this phenomenon. The other native fruits did not improve the sexual behavior of males. Implications of our findings in the management of A. fraterculus sp. 1 are discussed.