Flower constancy of the stingless bee Trigona carbonaria Smith (Hymenoptera : Apidae : Meliponini)

We tested the constancy of floral choice by Trigona carbonaria Smith in a garden by examining, using a scanning electron microscope, the composition of the pollen loads of individual foragers over time. Constancy was tested on three levels. Within a single trip, 88% of the samples examined comprised pure pollen loads (97% or more of one pollen type). Within a single day, 88% of bees visited the same species across trips sampled. Across 2 and 3 days, 82% and 73%, respectively, of individual bees foraged on a single pollen type. The majority of the remaining bees collected only two species of pollen. This pattern is consistent with that of other highly social bees. It enhances the pollinator efficacy of these insects by increasing the chances of pollen being transferred to stigmas of the same plant species. This increases the ecological importance of these bees and their value in crop pollination.