Olfactory Response of the Mexican Fruit Fly (Diptera: Tephritidae) to Citrus aurantium Volatiles

We investigated the behavioral and electrophysiological responses of male and female Mexican fruit fly, Anastrepha, ludens (Loew) (Diptera: Tephritidae), to volatiles of bitter orange fruit, Citrus aurantium L. In field cage tests, the number of A. ludens caught in Multilure traps baited with mature green bitter orange fruit was significantly higher than the number captured in traps baited with ripe yellow bitter orange fruit and control (unbaited traps). Both sexes were more attracted to mature green bitter orange fruit extracts than to controls in both flight tunnel and field cage assays. Gas chromatography-mass spectrometry analysis of the mature green bitter orange fruit volatiles identified 10 different compounds. Limonene was the most abundant volatile compound, followed by an unknown compound, tentatively identified as trans-ocimene. Linalool, beta-pinene, and methyl salicylate were found in lower proportions. Both sexes of A. ludens evoked higher antennal response to linalool, methyl salicylate, and to a blend of these four components in comparison with limonene, and beta-pinene. In flight tunnel, both sexes were more attracted and landed more often on spheres baited with the four-component blend compared with control spheres. In field cage tests, Multilure traps baited with the four-component blend captured significantly more A. ludens flies than traps baited with hydrolyzed protein or control traps.