Diet impacts on Melipona flavolineata workers (Apidae, Meliponini).
Luciano Costa and Giorgio Cristino Venturieri.
Stingless bees use nectar and pollen as their main food resources, and several alternatives to them have been investigated for beekeeping. This study evaluated nutritional alternatives for the Amazonian stingless bee Melipona flavolineata, looking for a substitute for honey and processed pollen. The following food replacements were compared to honey (H1): inverted sugar syrup with minerals (H2); inverted sugar syrup with amino acids and vitamins in the following concentrations: 0.5 % (H3), 1.0 % (H4) and 10 % (H5). To substitute for processed pollen (P1), we tested foods inoculated with M. flavolineata processed pollen, which consisted of commercial pollen of A. mellifera (P2); brewer's yeast (P3); and soybean extract with two different protein concentrations: 12 % (P4) and 18 % (P5). The nutritional value of the diet was assessed on the daily intake, on the size of hypopharyngeal gland acini and on the size of oocytes. Among the alternatives to honey, there were no significant differences between the control and the other treatments. Differences were found only between the sizes of acini of workers that were fed with H2 and H4, whilst treatment H4 was superior. Among the alternatives to processed pollen, consumption of treatment P4 was significantly greater than treatment P3, indicating a greater acceptance of soybean extract compared to yeast. For the other parameters evaluated, treatment P5 was superior to all the others. We concluded that the best alternatives for the nutrition of M. flavolineata are the sugar inverted syrup with minerals, and semi-artificial processed pollen based on soybean extract (P5: 18 % protein). These alternatives are arguably the safest diet supplements amongst those tested since they do not include hive products from other bees.