When bumble bee queens emerge from hibernation, they need to gather pollen and nectar to start their new colonies. If they wake up too soon, there may not be enough flowers in bloom. Now, researchers have discovered the bees have a way to order some fast food: They nibble holes in leaves, spurring plants to blossom weeks ahead of schedule. Many questions remain about the details of this strategy and how it evolved.
“It’s certainly surprising,” says Lars Chittka, a behavioral ecologist at the Queen Mary University of London, who was not involved. “We’re only at the beginning of exploring this phenomenon.”
Researchers at ETH Zürich chanced upon the discovery when they noticed curious bite marks on leaves while studying how bees respond to plant odors. They had added bumble bees to a research greenhouse and observed them cutting holes in the shape of half-moons. What was going on? At first, the researchers thought the insects might be feeding on fluid from the leaves, but the bees didn’t stay long enough to get much. Nor did they appear to be taking any part of the leaves back to their colonies.