Rising global temperatures may be making bumblebee nests too hot for them to survive.
The global bumblebee population has declined since the 1950s, sparking speculation on the causes 鈥� researchers have suggested everything from pesticides to habitat loss. Because bumblebees are vulnerable to temperature swings, some have proposed another culprit: climate change.
Researchers from the University of Guelph in Canada reviewed studies dating back to the 1800s and found that, regardless of species or region, bumblebees prefer a nest temperature between around 28 and 32掳C (82-90掳F). When nest temperatures surpassed 36掳C (97掳F), the bees couldn鈥檛 continue reproducing, adding new evidence to the idea that increased heat could be partly to blame. Because the larvae 鈥� young bees that resemble worms 鈥� are more sensitive to heat than adults, one brutal heatwave could kill a nest鈥檚 next generation.
Advertisement
鈥淚t鈥檚 remarkable that all the way from the high Arctic to the tropics, bumblebees seem to have the same sort of nest temperature requirements,鈥� says at the University of Guelph. 鈥淚f it gets too hot鈥� it鈥檚 quite likely that they will die.鈥�
Bumblebees protect growing larvae by fanning their nest with their beating wings. But this defence may not be enough to compensate for worsening climate change. High-tech innovations like a robotic 聽could offer some insurance for commercial honeybee operations, says Kevan, but aren鈥檛 a practical solution for roaming wild bees.
It is still crucial to consider other bumblebee threats, like pesticides and habitat loss. Efforts like planting native wildflower gardens can create much-needed habitat, but without also addressing warming, says Kevan, bumblebees may face a harrowing future.
Frontiers in Bee Science
