Endocrine cells in the midgut of insects produce and release neuropeptides such as FMRFamide and FaRPs which modulate muscle contraction and affect peristalsis. This study evaluated the number of midgut endocrine cells in workers of the stingless bee Scaptotrigona xanthotricha (Apidae: Meliponini) of different age and having received different diets. Workers of S. xanthotricha were fed on three different diets: honey, pollen, or honey plus pollen. The midgut of the bees was dissected when they were at 15 and 25 days old. The gut samples were analyzed by immunofluorescence, immunohistochemistry, and FMRFamide cells were subjected to ANOVA to verify the relationship between age and diet on the number of cells. There were no differences in the number of FMRFamide positive cells of the midgut of bees fed the different diets. Twenty-five day old bees showed 3.47 times more FMRFamide positive midgut cells compared to 15 day old bees. The greater number of FMRFamide positive cells in the midgut epithelium of 25 day old bees is related to physiological differences due to bee aging.