Influência dos compostos voláteis comuns ao feromônio sexual e aos frutos hospedeiros no comportamento reprodutivo de machos de Anastrepha obliqua (Diptera: Tephritidae)

Abstract

The fruit fly Anastrepha obliqua (Diptera: Tephritidae) represents one of the main pests of fruit growing worldwide, since it is a polyphagous insect whose larva feeds on fruit pulp, causing great economic losses for producing and exporting countries. A promising tool for the integrated management of this pest is the use of baits based on volatile compounds from host fruits combined with the sex pheromone of males. In order to understand the role of volatile organic compounds present in the mixtures released by host fruits and by virgin males of this insect pest, in different stages of reproductive behavior (calling and copulation), this study aimed to evaluate the effect of formulations of mixtures of common compounds the pheromonal mixture released by virgin males of A. obliqua and the host fruits guava, carambola and mango in the attraction and sexual performance of males. The compounds common to the pheromonal mixture and to the three host fruits were obtained through comparisons of data from the literature, where the volatile constituents released by virgin males of A. obliqua and by their host fruits, guava, mango and carambola, were extracted and identified by the use of aeration techniques, two-dimensional gas chromatography coupled to mass spectrometry (GC×GC-MS) and one-dimensional gas chromatography coupled to mass spectrometry (GC-MS). The attractiveness bioassays were performed in a double-choice glass arena, and the sexual performance evaluation tests were conducted only in a glass arena. The data obtained were analyzed by Wilcoxon and chi-square tests, respectively, with p≤0.05. The results showed that all formulations derived from compounds common to guava and the pheromonal mixture (M1FG, M2FG, M3FG, M4FG and M5FG) attracted as much as the formulation of the mixture of guava extract with male extract. When evaluating the results of the effect of exposing males to these same formulations, it was observed that only the M1FG mixture increased the number of matings of exposed males. For the formulations derived from the common compounds carambola and the pheromonal mixture, only the mixtures M2FC, M3FC and M4FC were attractive to males. Bioassays evaluating the effect of male exposure showed that no formulation derived from carambola fruit influenced the mating behavior of A. obliqua males. As for the tests with the formulations consisting of compounds common to mango and the pheromonal mixture, it was observed that the mixtures M2FM, M3FM, M4FM exerted similar attractiveness to the control treatment (mixture of mango aeration with male aeration). It was also observed that the M1FM mixture attracted less than the control and the M5FM mixture exerted greater attractiveness than the control treatment. The number of matings of males exposed to the M1FM, M2FM and M4FM mixtures was higher when compared to non-exposed males. Thus, it is possible to conclude that the formulations that are attractive to A. obliqua males, as well as the formulations that help to increase their sexual performance, have great potential for use in control and monitoring strategies for this insect pest in the field.