New Scientist report:-   “Hungry bumblebees can coax plants into flowering and making pollen up to a month earlier than usual by punching holes in their leaves.

Bees normally come out of hibernation in early spring to feast on the pollen of newly blooming flowers. However, they sometimes emerge too early and find that plants are still flowerless and devoid of pollen, which means the bees starve.

Fortunately, bumblebees have a trick up their sleeves for when this happens. Consuelo De Moraes at ETH Zurich in Switzerland and her colleagues discovered that worker bumblebees can make plants flower earlier than normal by using their mouthparts to pierce small holes in leaves.”

Read more:

https://www.newscientist.com/article/2244009-bees-force-plants-to-flower-early-by-cutting-holes-in-their-leaves/