SEXUAL DIMORPHISM IN CUTICULAR HYDROCARBONS OF THE RED PALM WEEVIL, Rhynchophorus ferrugineus (OLIVIER) IN RELATION TO MATE CHOICE

Document Type : Original Article

Authors

Pl. Prot. Res. Inst. (PPRI), Agric. Res. Cent. (ARC), Egypt

Abstract

Patterns of sexual dimorphism in the cuticular hydrocarbons of the red palm weevil, Rhynchophorus ferrugineus (Olivier) were analyzed using gas chromatography/mass spectrometry. A preliminary GC-MS analysis (retention time and EI mass spectrum) of dichloromethane cuticular extracts indicated that males and females share19 components above trace level. Ten of the 19 peaks found in our GC chromatographs, differed in their peak areas and relative abundance between the sexes. In mating bioassays, males attempted to mate with live and freeze-killed females, but did not respond to dead females after cuticular hydrocarbons were washed by dichloromethane, indicating that mate recognition was mediated by sex-specific contact sex pheromones. The occurrence of sexual dimorphism in cuticular hydrocarbons, together with the behavioral results supported the suggest that certain female hydrocarbons mediate mating behavior of the R. ferrugineus weevil and provide the first evidence of contact pheromones in Rhynchophorus species.

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