Diversity of stingless bees (Hymenoptera: Apidae) from two contrasting climatic regions of Nigeria

Stingless bees are one of the major pollinators of crop plants and also produce honey, which is often harvested for human consumption. Information on the diversity of stingless bees varies with climatic region. The taxonomy of African stingless bees, in particular, is largely limited to morphological traits and requires updating with current molecular methods in order to resolve cryptic variation within the group. This study employed integrative taxonomy to document stingless bee fauna of two climatic regions of Nigeria. Stingless bees were collected from Jos – a montane ecosystem at an elevation of about 1,500 m above sea level (a.s.l.) and Nsukka – a tropical ecosystem at an elevation of about 460 m a.s.l. Morphological features and molecular characterisation using three gene regions (COI, 28S rDNA and elongation factor) were employed to identify and update the taxonomy of the species. Seven species of stingless bees were recorded in the study – four species occurred only in the tropical ecosystem; one species in the montane ecosystem, while two species occurred in both ecosystems. Species diversity was higher in Nsukka than in Jos with Simpson’s indices of 0.697 and 0.643, respectively. Species delineation of the three genes aligns with species’ morphology. A new species Axestotrigona nigerrima sp.n. Onah and Sumner is proposed based on the observed differences in morphological, molecular and distributional data. These results provide a much-needed revision of the taxonomy and documentation of species distribution for these ecologically and economically important insects, from an understudied part of the world.