Bumblebee queens can survive underwater

April 18 () –

Bumblebee queens survive prolonged periods of total submergence while wintering underground, an unexpected finding from a team at the University of Guelph.

Bumblebees are crucial pollinating insects, known for their importance in ecosystems around the world. During the cold season, queen bumblebees retreat underground to spend the winter in small burrows.

They typically seek out well-drained soil, often in banks, to hibernate until spring arrives. It is likely that these soil characteristics serve to protect them from flooding, a potentially fatal threat to many terrestrial organisms.

The discovery made by the University of Guelph team, detailed in Biology Lettersarose from a unexpected experimental error when water accidentally flooded containers housing hibernating bumblebee queens.

“When I found the queens submerged, I drained the water from the tubes and the queens were still alive. I was surprised,” he recalls. it's a statement postdoctoral researcher Dr. Sabrina Rondeau, author of the study.

This led researchers to delve deeper into this mystery. The study involved exposing commercially raised bumblebee queens to a variety of dipping treatments while they overwintered under controlled conditions.

Surprisingly, queens kept underwater for up to seven days did not show lower survival rates compared to the control group not exposed to water.

“Floods are an unpredictable challenge for ground-dwelling species, particularly bees that nest or overwinter underground,” Raine said. “This area of ​​research has remained largely unexplored until now, opening many avenues for future research.”

Bumblebee queens' tolerance to submergence occurs during diapause, a state of suspended growth and reproduction characterized by reduced oxygen intake.

Rondeau explained: “Insects breathe through spiracles, not nostrils like humans. During diapause, the spiracles may remain closed for long periods, preventing water from entering the body.” Submerged bumblebee queens may also use cuticular respiration (cutaneous respiration), facilitated by air bubbles trapped on the surface of their body .

The findings underscore the need to further investigate the mechanisms behind bumblebee resilience, especially in the context of escalating extreme weather events.

As climate change intensifies, insights from this study could inform strategies to conserve these vital pollinators and the ecosystems they support.