Cuticular hydrocarbons from two species of Malaysian Bactrocera fruit flies

Abstract The cuticular hydrocarbons of two Malaysian taxa (Malaysia A and Malaysia B) of the Bactrocera dorsalis complex were analysed by gas chromatography and gas chromatography-mass spectrometry. Significant quantitative differences in the distribution of hydrocarbons of different chain lengths, mainly the 31-, 33- and 35-carbon backbone compounds of these two species were observed despite indistinct qualitative differences in these hydrocarbons. The cuticular hydrocarbons of Bactrocera Malaysia A and B. Malaysia B (denoted as BMA and BMB respectively) comprised n -alkanes, terminally branched monomethylalakanes, internally branched monomethylalkanes, and dimethylalkanes. Hydrocarbons with the parent chain of 33 carbons predominate in these two species. The most abundant components present in the hydrocarbon mixture of BMA are the isomeric mixtures of C 33 internally branched monomethylalkanes while in BMB, are the isomeric mixtures of C 33 dimethylalkanes. The major n -lakanes present in both species were n -hentriacontane and n -tritancontane. The major components of terminally branched monomethylalkanes in BMA were 30-methylentriacontane and 3-methyltritriacontane, while in BMB was 3-methylhentriacontane. In BMB, the internally branched monomethylalkanes were predominated by isometric mixtures of C 31 and C 33 . The major dimethylalkanes in BMA were the isomeric mixtures of C 33 and C 35 . Statistical comparisons of the citucular hydrocarbon compositions of the two species by canonical discriminant analysis show distinct interspecies identities.