Pollen loads of pollinator bees of Byrsonima chrysophylla Kunth. (Malpighiaceae): fidelity and alternative sources of flower resources

Byrsonima chrysophylla, known as murici pitanga, is a shrubby species occurring in 'restinga'. Among its visitors, bees of the Centridini tribe as well as Xylocopini bees are frequently found. To detect which plant species have been used by the most frequent visitors, pollen loads from the back legs (n = 5) and also from natural nests of Centris caxiensis (n = 7) were treated by acetolysis. During flowering of Byrsonima chrysophylla, this plant species was the main pollen source used by bees. Comolia lythrarioides and Myrcia sylvatica were secondary pollen sources, Mouriri guianensis was a secondary oil and pollen source, while Anacardium microcarpum, Cuphea tenella, Matayba discolor and Phthirusa pyrifolia were important nectar sources at this time. The pollen detected in the samples probably adhered to the bee's body during nectar collection. The results show that the bee visitors do not mix pollen sources during the pollen-collecting flight, thus representing fidelity to Byrsonima chrysophylla flowers.