An experimental error led a team of scientists researching bumblebees to make a startling discovery: the insects’ remarkable ability to survive underwater for up to a week.
A study published in the journal Biology Letters on Wednesday described how scientists from Canada’s University of Guelph accidentally submerged hibernating queen common eastern bumblebees in water, and were astonished to find that they had survived.
Study author Nigel Raine, a professor in the school of environmental sciences at the university, told CNN that it was “really surprising.”
“These are terrestrial organisms, they’re not really designed to be underwater,” he said.
The team then carried out an experiment involving 143 common eastern bumblebee queens and found that those kept under water for periods of up to seven days had similar survival rates to those not kept under water, according to a statement from the university.
“We found very little impact of any of the submersion regimes,” Raine told CNN.
This is the first time that scientists have tested how bumblebee queens fare when submerged for long periods, and the findings shed new light on the insects’ adaptations and their resilience to flooding.
During the cold season, queen bumblebees hibernate alone after male and worker bees die out at the end of autumn, Raine explained.
They overwinter in small burrows, usually in well-drained soil in banks, he added.
Scientists believed that these conditions provide protection from flooding, which would be fatal to many terrestrial organisms, but the study shows that eastern common bumblebees can survive for at least a week.
“We don’t know much about this critical phase in their life history,” he said. “We’re starting to scratch the surface of what’s going on underground.”
While this study did not examine how the bees are able to survive, one possible explanation is that they are in diapause, said Raine, which is “a state of suspended growth and reproduction characterized by reduced oxygen intake,” according to the statement.
During diapause, respiratory openings known as spiracles can close for extended periods and stop water from entering the body, and submerged bumblebee queens may also breathe through their skin, the researchers said.
“These bees are effectively on energy-saver mode,” said Raine, who added that they most likely wouldn’t survive underwater if they were active.
Understanding the mechanisms behind this resilience is a key question for future research, said Raine, who also plans to test whether hibernating queens could survive for longer than a week underwater.
“It could be substantially longer than that,” he said,
Raine also plans to research whether other bee species have similar resilience to submersion.
“Understanding wild pollinators is really, really important,” he said, emphasizing the insects’ importance for food security and terrestrial ecosystems.
