Aphid species identification using cuticular hydrocarbons and cytochrome b gene sequences

In Tunisia, four major aphid species have been identified based on adult female's morphological characters: Aphis gossypii Glover, Aphis craccivora Koch, Myzus persicae Sluzer and Macrosiphum euphorbiae Thomas. Species identification at individual collection sites is often difficult because adults are much fewer in number than larvae which are not so easy to distinguish morphologically. We therefore set up an experiment to determine if cuticular hydrocarbon phenotypes and mitochondrial DNA haplotypes could be used to distinguish such sympatric species. Results showed that each species had an unique cuticular hydrocarbon phenotype and mitochondrial cytochrome b sequence. Cytochrome b restriction fragment‐length polymorphism markers, especially DdeI, identified in this sudy constitute a relatively simple and useful approach to distinguish the four species even at the nymphal stage.