Palynological examination of the pollen pots of native stingless bees from the lower Amazon region in Para, Brazil

This is the first palynological study using pollen stored by Tetragonisca angustula (Apidae: Meliponini) in the Lower Amazon region, Para, Brazil. The samples were directly collected from the pollen pots of T. angustula in apiaries located in Belterra and Santarem. The samples were dried, weighed, diluted in warm water and ethanol, centrifuged and then processed using the acetolysis method. After mounting the samples on slides, we identified and counted at least 500 pollen grains per sample. The results indicate that the main pollen combinations in the pollen pots of T. angustula in Belterra include pollen from Byrsonima, Cecropia and Eriope, and the combinations from Santarem include pollen from Byrsonima, Cecropia, Clidemia hirta, Davilla kunthii, Myrcia and Vismia guianensis. Most pollen types came from the families Fabaceae and Asteraceae. The pollen diversity (H') ranged from 0.03 to 1.95, and the evenness (J') ranged from 0.04 to 0.79, with the average trend indicating heterogeneity in the collection pattern. Temporary specialisation events typified five of the samples that we studied, directly detecting pollen from Byrsonima, Cecropia and Clidemia hirta. Such events appear to be unrelated to the direct processes of effective pollination. The pollen spectra obtained corroborate the pollen types that have previously been described in palynological analyses involving Tetragonisca angustula in other areas of Brazil.