Pollen preferences of stingless bees in the Amazon region and southern highlands of Ecuador by scanning electron microscopy and morphometry

Abstract

Stingless bees are effective pollinators of native tropical flora. Their environmental service maintains flow of pollen through pollination, increase reproductive success and influence genetic structure in plants. The management of stingless bees “meliponiculture”, is an activ ity limited to the countryside in Ecuador. The lack of knowledge of their managers about pol len resources can affect the correct maintenance/production of nests. The objective is to identify botanical families and genera of pollen grains collected by stingless bees by mor phological features and differentiate potential species using geometric morphometry. Thirty six pot pollen samples were collected from three Ecuadorian provinces located in two climat ically different zones. Pollen type identification was based on the Number, Position, Charac ter system. Using morphological features, the families and genera were established. Morphometry landmarks were used to show variation for species differentiation. Abun dance, diversity, similarity and dominance indices were established by counting pollen grains, as well as spatial distribution relationships by means of Poisson regression. Forty six pollen types were determined in two study areas, classified into 27 families and 18 gen era. In addition, it was possible to identify more than one species, classified within the same family and genus, thanks to morphometric analysis. 1148 ± 799 (max 4211; min 29) pollen grains were counting in average. The diversity showed a high richness, low dominance and similarity between pollen resources.