Identificação dos constituintes químicos do feromônio sexual de populações de Anastrepha fraterculus (DIPTERA:TEPHRITIDAE) e de seu fruto hospedeiro preferencial, Goiaba - Psidium guajava (Myrtaceae)

Abstract

The fruit flies are phytophagous insects widely distributed in the tropics and cause significant financial losses to fruit growing due to the damage caused by their larvae when they infest the fruits, at domestic or commercial orchards. Anastrepha fraterculus (Wiedemann, 1830) is the pest of major economic importance within the genus, and for this reason several groups have developed studies to elucidate strategic questions about the biology of these insects. A importante point of the studies with A. fraterculus deals with the existence of 8 different intraspecific morphotypes that, due to the geographic isolation of these populations and of feeding habits, confer to these populations morphological and chemical characteristics, related to the composition of the sexual pheromone, different features between them. In addition, the tephritids present an intimate relationship with their hosts, which reinforces the need to conduct a study aiming to find which chemical compounds are involved in this interaction and which additional aspects should be considered in the elaboration of sustainable monitoring and control strategies. The aim of this work was to characterize the populations of six different localities by means of two-dimensional gas chromatography coupled to mass spectrometry, evaluating the degree of isolation of these populations from the differences between volatile compositions released by male insects and identifying which solutions of synthetic compounds present in extracts of the host fruit (guava), which concentrations and which combinations of these would be effective in tests of attractiveness with virgin and mated females, 9, 12 and 15 days old. The compounds, for example (R)-(+)-limonene; ethyl octanoate; α-copaene and α-trans-caryophyllene, were tested in the laboratory, in addition to having been proposed the use of a biopolymer, whose purpose is to serve as a substrate for use with the formulation of attractive baits in traps. It was used extracts obtained by aeration of fruits and insects to identify their compositions and to perform bioassays with females of this species, in glass sand. The study revealed that there are significant differences in the chemical composition of the pheromone released by males among the studied populations; that A. fraterculus females respond to individual solutions and mixtures of synthetic compounds found in hosts, influenced by their age and mating status; and that the biopolymer used had potential for sustained dispersion of the volatile compounds used.