O'Connor, Timothy K.Starr, Christopher.KCameron, Sydney A.2012-06-282012-06-282012-06-28https://hdl.handle.net/2139/13083In Trinidad, West Indies, wasps matching the description of Mischocyttarus alfkenii build two readily distinguishable nest forms, differing both in architecture (excentric versus centric petiole) and colour (yellowish grey-brown versus reddish medium brown). Analysis of two mitochondrial genes (16S and cytochrome c oxidase subunit I, COI) in excentric- and centric-form M. ‘alfkenii’ consistently segregates individuals from the two nest forms, with genetic divergences comparable with those observed among other species in the genus. Geometric morphometric analysis of wing venation likewise recovers consistent differences between nest forms. Integrating behavioural, genetic and morphometric evidence corroborates the hypothesis that the two nest forms correspond to distinct species of recent common ancestry. Notes accompanying the description of M. alfkenii indicate that the name belongs to the species in which the nest has an excentric petiole and paler carton. The other species is described as Mischocyttarus baconienArticle