Stingless Bees Fed on Fermented Soybean-extract-based Diet Had Reduced Lifespan than Pollen-Fed Workers

Abstract

Nectar and pollen are the basic food resources of stingless bees. The current advance of meliponiculture led to the search for supplementary feeding. Despite little is known about native bee supplementation, several alternative foods have been tested as protein substitutes, with soy being one of the most commonly used. In this study, we compared the effect of a semiartificial soy-based diet versus a natural diet on the longevity of adult worker of Melipona flavolineata Friese and Scaptotrigona aff. postica (Latreille). A total of 200 workers of each species (40 from each colony) were used, of which 100 comprised the control group (consumed honey and pollen) and 100 the experimental group (honey and a semiartificial food based on soybean extract). The workers were divided into groups of 20 individuals confined in MDF boxes not completely enclosed, without a queen, and kept in BOD incubators. Dead bees were counted and removed daily. Kaplan-Meier survival curves were plotted for each species. We found greater longevity in workers who consumed only natural pollen (71 days for M. flavolineata, 78 days for S. aff. postica, in average) compared to those consuming the soy-based diet (62 days for M. flavolineata, 61 days for S. aff. postica, in average). Workers of M. flavolineata that consumed pollen lived nine days more (21.8%) than those fed on the soy-based diet, while S. aff. postica workers lived seven days more (12.7%). As longevity was only slightly reduced, we can recommend a soy-based diet for stingless bees during dearth periods or for supplemental feeding of newly formed colonies.