Discriminating unifloral honey from a dioecious mass flowering tree of Brazilian seasonally dry tropical forest through pollen spectra: consequences of honeybee preference for staminate flowers

Abstract

Myracrodruon urundeuva (“aroeira”) is a dioecious tree of the seasonally dry tropical forest (SDTF) of Brazil and source of a unique unifloral honey. To discriminate this honey by its pollen spectra, we compared melissopalynological analysis of reference honey samples with those of other samples collected in the SDTF belt. Reference honeys had on average 99% of aroeira pollen, while the other honey samples averaged 84% of this pollen. We used the receiver operating characteristic (ROC) curve, applied here for the first time in honey analysis, for determining the cut-off value of at least 93% of Myracrodruon pollen in a sample for classifying unifloral aroeira honey. The over-representation of aroeira pollen in this honey reflects that honeybees visited ten times as many staminate flowers as pistillate flowers. We conclude that unifloral aroeira honey has uniform pollen spectra, as a byproduct of the preference of honeybees for staminate flowers.