Species variability in afrotropical genus hypotrigona (cockerell) within three districts in the Central Region of Ghana

Abstract

This research was carried out to investigate the species variability within Afrotropical stingless bees of the genus Hypotrigona (Cockerell) in three districts in the Central Region of Ghana. Hypotrigona species are common visitors to flowering plants in the tropics and subtropics. Structurally, the three known Afrotropical Hypotrigona species are very similar and pose difficulty in accurately identifying existing species. In view of this taxonomic impediment, this present study aimed at investigating variation within the Afrotropical genus Hypotrigona based on their nest entrance characteristics, the geo-morphometry of their wings and the traditional morphometry of the bees within three districts in the Central Region of Ghana. The research was conducted from April 2013 to November 2013. A total of 5441 bees were sampled from 68 colonies. Using nesting characteristics, geometric morphometrics and traditional morphometrics, three probable species were observed in the study. Precisely 2027 individual right forewings of Hypotrigona bees were assessed using geometric morphometrics. Statistical analyses (PCA, CVA, DFA, correlation and Procrustes ANOVA) conducted on the right forewings were statistically significant p <0.0001. All three protocols used for assessing variability identified three different species within the genus as Hypotrigona gribodoi, Hypotrigona araujoi and Hypotrigona ruspolii. Nest entrance characteristics were found to be highly variable in terms of level of aggression and entrance tube length. All three protocols; were effective in distinguishing species within the genus Hypotrigona and are recommended for taxonomic analysis of the Afrotropical Hypotrigona species.