Morphometric and genetic analyses show differentiation of the widely distributed stingless bee Nannotrigona perilampoides (Hymenoptera: Meliponini) across geographic regions in Mexico

Abstract

Stingless bees are a diverse group of insects that contribute a wealth of fauna to Central America, as well as being important pollinators. Colonies of these stingless bees are managed and transported unregulated across geographic regions on the basis that they are native species. Populations of Nannotrigona perilampoides, one of the most common stingless bee species in Mexico and Central America, are separated by several geographical barriers that may act as obstacles to gene flow. In addition, their biological and reproductive characteristics make them susceptible to variation among their populations. In this work, we combined morphometric and molecular analyses (through cox1, 16S, ITS1 and ITS2 sequencing) to test whether there is a differentiation between distant populations of N. perilampoides separated by the Sierra Madre Mountain complex. Analyses of wing geometric morphometrics and sequence variation of a fragment of the 16S gene revealed significant differences between populations. These differences show a pattern of isolation by distance, and the possible effect of the Sierra Madre as a biogeographical barrier. The results suggest that N. perilampoides may be composed of distinct evolutionary units and that colony exchange among regions should be restricted to preserve the diversity of this species.