Cuticular Hydrocarbons of Anastrepha obliqua (Diptera: Tephritidae) as Influenced by Extraction Method, Natal Host, and Age

Abstract

The primary function of cuticular hydrocarbons is to keep insects from losing water. However, cuticular hydrocarbons also may mediate chemical communication in a number of species. In this study, we investigated the effect of the extraction method, natal host, and age (maturation) on the cuticular hydrocarbon profiles of the West Indian fruit fly, Anastrepha obliqua (Macquart) (Diptera: Tephritidae). Cuticular hydrocarbons from female and male adults of different natal hosts (Mangifera indica L. or Spondias mombin L. [both Anacardiaceae]) and age were extracted by solvent extraction and direct contact solid-phase microextraction. Cuticular hydrocarbons were identified by gas chromatography coupled to mass spectrometry. In total, we recorded 12 compounds, but only 9 of them were identified. The identified cuticular hydrocarbons were linear alkanes (n-heneicosane, n-nonacosane, and n-hentriacontane), alkenes (n-heneicosene, n-tricosene, n-nonacosene, and n-hentriacontene), and branched alkanes (2-methyl-octacosane and 2-methyl-triacontane). There were no qualitative differences between sampling techniques. The solvent extraction method extracted more cuticular hydrocarbons from flies reared on mango compared to those extracted from flies reared on hog plum. In contrast, solid-phase microextraction extracted a higher concentration of cuticular hydrocarbons from flies reared on hog plum than to those extracted from flies reared on mango. Higher levels of 2-methyl-octacosane and 2-methyl-triacontane were detected with solvent extraction than with solid-phase microextraction; the opposite occurred with hentriacontane and unknown compound 2. The compounds n-heneicosene, n-heneicosane, and n-tricosene were present in mature males but not in mature females; n-nonacosene was found only in the mature flies of both sexes.