Does Helping Your Mom Pay Off? Queen Bee Pheromones Help Daughters Decide Whether to Stay or Leave the Nest

Queen pheromones in Megalopta bees tell daughters when it’s worth sacrificing their fertility to help their mom

Imagine if moms could give their daughters a magic potion that would determine whether they stay at home to help them or leave and form their own families. Scientists at the Smithsonian Tropical Research Institute (STRI) study queen pheromones, chemicals secreted by the queen in social insects such as bees, ants and wasps. In a new paper, STRI and Princeton University postdoctoral fellow Callum Kingwell, and STRI staff scientist Bill Wcislo identified for the first time, queen pheromones in a species of sweat bee that can either be social or solitary. Previously, studies of queen pheromones have been limited to species that always form social colonies.

These findings were published in the journal Proceedings of the Royal Society B, a particularly appropriate home for a study about queens.

Researchers studied the sweat bee Megalopta genalis, which is of special interest, because the queen’s daughters may either stay as worker bees who do not reproduce and help the queen in a social nest, or they can leave and found their own nests, either as solitary queens or founders of new social nests. Given this interesting flexible behavior, M. genalis offers a unique opportunity to study the evolutionary origin of sociality.

Fieldwork was conducted on Barro Colorado Island (BCI), where researchers studied around 450 artificial bee nests placed in their natural habitat over multiple years. The team marked individual bees, video-recorded their behavior, and identified and quantified the chemicals coating the bees' bodies using advanced analytical techniques, including gas chromatography coupled with mass spectrometry. They also recorded if the daughters stayed and worked for the queen, usurped the queen, or left the nest to reproduce elsewhere.

Scientists found that just like that magic potion, queen pheromones induce subordinate behavior and inhibit the daughters' investment in reproduction, as levels of queen pheromones were higher in social nests relative to solitary nests. By reliably advertising queens’ future egg-laying potential, this pheromone allows daughters to decide whether to stay and help their mom queen is a worthwhile investment, or if they should leave and form their own colony.

“Chemical signals like these may stabilize nascent insect societies, buying time for social complexity to emerge over evolutionary time,” said Wcislo. “This represents, to our knowledge, the first queen pheromone identified for a flexibly social insect,” he added.

“A particularly novel aspect of this study was performing chemical analyses directly on Barro Colorado Island and repeatedly sampling live bees, allowing us to track chemical signaling in the same free-living individual bees throughout their lives. These observations provide a rare window into how insect societies may first evolve,” said Kingwell.

Highly social insects dominate ecosystems worldwide as workers forgo reproduction to support their queens, but the evolutionary origins of sociality remain poorly understood. Megalopta bees, a group found only in the Americas, are thought to represent one of the most recent origins of societies among bees, wasps, and ants. This discovery sheds new light on the chemical mechanisms that may have helped social life evolve.

“The evolution of cooperation is a fundamental question that extends far beyond insects. Our work shows how chemical communication can help individuals decide when cooperation is worthwhile, offering insights relevant to evolutionary biology, animal behavior, and social systems generally,” explained Kingwell.

Reference: Kingwell, C. & Wcislo W. A queen pheromone signals the benefits of cooperation in a flexibly social insect. 2026. Proceedings of the Royal Society B. https://doi.org/10.1098/rspb.2026.0506.

About the Smithsonian Tropical Research Institute

Headquartered in Panama City, Panama, STRI is a unit of the Smithsonian Institution. Our mission is to understand tropical biodiversity and its importance to human welfare, to train students to conduct research in the tropics and to promote conservation by increasing public awareness of the beauty and importance of tropical ecosystems. Watch our video, and visit our website, Facebook and Instagram for updates.

Rosannette Quesada Hidalgo | Read More

Rosannette Quesada H. is an enthusiastic behavioral ecologist based in Panama City, Panama. She is also a science storyteller and the founder of the science communication initiative Opilio Tracker, a project promoting appreciation for arachnids.