This study was designed to identify important food resource plants used by bee species in a Caatinga area, as well as describe the local patterns of floral use by bees. A total of 1,145 foraging bees, belonging to 60 species, were captured while visiting 50 plant species. Melochia tomentosa L., Sida galheirensis Ulbr., Erythroxylon catingae P. Cowan, and Ziziphus cotinifolia Reiss. were the most frequently visited plants. Melochia tomentosa, Solanum paniculatum L. and S. galheirensis were visited by larger number of bee species. Some oligolectic bees were identified. Apis mellifera Linnaeus, 1758 and Trigona spinipes (Fabricius, 1793) had the largest trophic niche breadth (2.71 and 2.31). The trophic niche overlap was highest (0.52) between Xylocopa grisescens Lepeletier, 1841 and Frieseomelitta silvestrii (Friese, 1902). The low trophic niche overlap between Apis mellifera and native stingless bees seems to be the result of intensive exploration of only a few flower sources by Africanized bees, not frequently visited by meliponids.
Bee plants; floral visitors assemblages; semi-arid northeastern Brazil; trophic niche
