Worker longevity in an Amazonian Melipona (Apidae, Meliponini) species: effects of season and age at foraging onset

Abstract

We studied the relationship between worker longevity and the age of foraging onset in the bee Melipona fasciculata, as well as the longevity oscillation in the rainy and dry seasons. Workers that emerged in the rainy season started to forage later and lived at least 50 % longer than foragers from the dry season. In both periods, a higher longevity was observed in workers that started to forage earlier in life but did not forage all days of their careers. We also showed, by using a Weibull model, that workers experienced higher mortalities at older ages in the rainy season, but the same model did not fit with the data from the dry season. This lack of fit in the dry season can be explained by the high mortality of workers that did not start to forage in this season and to other intrinsic factors of the colonies. Thus, the age of foraging onset and internal colonial factors must be considered in studies examining worker longevity in free-foraging colonies in this diverse group of eusocial bees.