Young female bees of the Megalopta genalis species face a crucial life choice: devote themselves to helping their mother in the natal nest or go in search of their own home. As representatives of the Smithsonian Tropical Research Institute (STRI) reported on the Phys.org website, it has been proven for the first time that queen pheromones play a key role in this decision.
As the daughters of these bees mature, they may follow one of two paths. Some remain in the nest as worker bees, forgoing their own reproduction. Others leave the maternal home to establish their own nest — either alone or by founding a new social colony.
Scientists hypothesised that the daughters’ choice might be linked to the queen’s health and to how promising an independent life outside the natal nest would be in terms of gene transmission. To find out whether the chemical signals emitted by the queen influence this choice, researchers conducted long‑term observations on Barro Colorado Island in the Panama Canal area. They placed hundreds of artificial nests in the bees’ natural habitat.
Each bee was marked, and its behaviour was recorded on video — this made it possible to track which daughters stayed as workers, which tried to take the queen’s place, and which left to reproduce elsewhere. The scientists then analysed the composition of substances on the insects’ bodies using gas chromatography and mass spectrometry — methods that allow precise identification and quantification of individual chemical compounds.
“The novelty of our work lay in the fact that the chemical analysis was carried out directly on Barro Colorado Island. We repeatedly took samples from live bees and monitored the dynamics of chemical signals in the same free‑living individuals throughout their lives,” explained Callum Kingwell, a postdoc at STRI and Princeton University.
The results showed that queen pheromones affect the daughters in two ways. At a certain stage of development, the level of these substances in the queen increases — and this suppresses the maturation of the daughters’ ovaries. In addition, the concentration of pheromones serves as an indicator of the queen’s reproductive health: the higher the level, the more often the daughters stayed to help their mother. Thus, chemical signals help young bees choose between supporting the family and reproducing independently.
Bill Wcislo, a staff scientist at STRI, emphasised that such chemical signals can prevent the disintegration of nascent insect communities and create conditions for the formation of more complex social structures. According to him, this is the first documented case of identifying a queen pheromone in a social insect with a flexible social organisation.
Earlier studies revealed the mechanism behind collective decision‑making in bee communities without centralised control. It turned out that a simple principle operates in the hive: a few of the most active individuals go out to collect nectar regardless of the weather, while most bees stay safe and join the foraging only when conditions improve. Despite the presence of a queen, she does not direct this process: the bees act together — scouts share information, and the rest of the colony responds to it.
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