Characterization of the orchid bee Euglossa viridissima (Apidae: Euglossini) and a novel cryptic sibling species, by morphological, chemical, and genetic characters

In orchid bees, males signal their availability as mates by fanning 'perfumes', i.e. blends of volatiles that are collected from environmental sources and stored in hind leg pouches. The chemical composition of such perfumes in males with either two or three mandibular teeth has previously led to the discovery of two sympatric, cryptic lineages within Euglossa viridissima Friese on the Yucatan peninsula, Mexico. Here, we combine chemical, morphological, and genetic data for an integrated characterization of the two lineages. The lectotype of E. viridissima Friese in the Museum of Natural History in Vienna has two mandibular teeth, and the species name viridissima must thus be assigned to the predominantly bidentate lineage, whereas the completely tridentate lineage is described as a novel species, Euglossa dilemma sp. nov. Bembe & Eltz. Chemical profiling and microsatellite genotyping revealed that E. viridissima males can occasionally (similar to 10% of individuals) express a third mandibular tooth, but this tooth is not positioned centrally on the mandible as in E. dilemma, but is displaced towards the tip. Thus, males of the two lineages can be unambiguously diagnosed by mandibular characters alone. Based on 889 bp of CO1 sequence data, we confirm that E. viridissima and E. dilemma constitute a monophyletic group within the genus Euglossa. However, CO1 alone failed to separate these two lineages due to the lack of parsimony-informative sites. Both species occur in broad sympatry across Central America, but the orchid bees recently introduced to Florida have three mandibular teeth in males, i.e. belong to E. dilemma. (C) 2011 The Linnean Society of London, Zoological Journal of the Linnean Society, 2011, 163, 1064-1076. doi: 10.1111/j.1096-3642.2011.00740.x