An advance in the in vitro rearing of stingless bee queens

Stingless bees are a diverse group of highly eusocial tropical bees and potential pollinators of natural and crop environments. Nevertheless, large-scale breeding for agricultural purposes still needs development. A bottleneck is the small number of queens generally found in the colonies of most species. A proposed solution is to develop in vitro rearing of stingless bee queens, which includes a technical support due to the massive liquid feeding of larvae. In this study, we tested the efficacy of in vitro queen-rearing techniques in terms of queen size, survival, and fecundity. We found that humidity must be kept high during the first 6 days of larval development and reduced thereafter to 75 %. In the most effective treatments, we obtained up to 97.9 % queen survival. We also found that queens not different in size from natural queens could be produced if sufficient larval food is provided. In vitro queens were able to mate and lay viable eggs. This methodology is also useful for several research appliances, like pesticide effect on bees, pollen quality effect in caste determination, and the use of genetic sources for selection programs, among others.