Cuticular hydrocarbons distinguish cryptic sibling species in Euglossa orchid bees

Cuticular lipid profiles have been shown to be species specific within many insect genera, allowing a chemotaxonomic classification of individuals. In this study, we analysed the cuticular lipids of the orchid bees Euglossa viridissima Friese and Euglossa dilemma Bembé & Eltz, cryptic sibling species whose taxonomic status has only recently been clarified. Male individuals of both species were obtained from two locations on the Yucatán Peninsula, Mexico, both in the dry and wet seasons. Their hydrocarbon profiles proved to be species specific, irrespective of location and season. They also allowed a correct assignment of a rare morph of E. viridissima which had long obscured the distinction of the two species. Our results suggest that cuticular hydrocarbon profiles may be suited for chemical taxonomy of orchid bees and might provide an additional clue for difficult species distinctions.