The queens of the stingless bees: from egg to adult

Abstract

Queens play an essential role in the colonies of stingless bees. Typically, only one queen occurs in a colony at any time, and she dominates the egg laying. Their presence maintains colony cohesion and ensures the development and survivorship of these matriarchal societies. Yet there remain significant gaps in our knowledge of queen life cycles as compared to their daughters, the workers. In this review, we follow chronologically the life of queens from pre-emergence inside brood cells (caste determination), to their interaction with workers (queen selection) and males (sexual selection), and up to adulthood. Stingless bee queens can be determined either trophically or genetically. After emergence, the virgin queens undergo a selection process whereby many are executed by workers. The body size, pheromones, age and behaviour of virgin queens may play a role in queen selection. Queens then leave the nest on a nuptial flight during which they mate just once. After mating, queens are still susceptible to workers’ harassment. For example, if they produce diploid males they are killed by workers. Previous studies have successfully in vitro reared and mated virgin queens under laboratory conditions, which have revealed new insights of queen development time, the threshold of minimum and maximum provided food to larvae developing into queens, and lethal and sublethal effects of agrochemical substances. These new techniques have also provided new information about queen physiology. However, the daily routine of queens inside colonies demands further well-designed experiments to capture other patterns of behaviour which remain poorly understood, including their interactions with other queens, workers and even males.