Male exposure to guava volatiles affects female remating behavior in Anastrepha fraterculus

Abstract

Plant-derived volatiles can have positive or negative effects on insects. Exposure to volatiles of guava (Psidium guajava L.) (Myrtaceae) enhances male mating success in the South American fruit fly, Anastrepha fraterculus (Wiedemann) (Diptera: Tephritidae), an important pest of various fruits. These volatiles can therefore be used as a post-teneral, pre-release supplement in sterile insect technique (SIT) programs. In SIT, mass-reared sterile males compete for and mate with wild females, in order to reduce populations of insect pests. However, the success of SIT will be diminished if males are not able to inhibit females from remating with other (potentially wild) males. Here, we investigated the remating propensity of A. fraterculus females mated with males exposed to guava volatiles or non-exposed (control) in choice and no-choice tests. In addition, we tested whether exposure to guava volatiles affected male reproductive organ size (testes, accessory glands, and seminal vesicles) and cuticular hydrocarbon (CHC) profile. Females mated with guava-exposed males were more likely to remate than females mated with control males, but there was no difference in the length of the refractory period (i.e., the time between the first and second mating event). Reproductive organ size did not differ between exposed and non-exposed males, but exposed males had a higher quantity of waxes than non-exposed males, and CHC profiles differed. The results are discussed in the context of SIT programs for the control of this insect pest.