Turning Up the Heat

Heat Ball

Left: Tethered Asian Hornet
Right: Japanese Bees Form Heat Ball Around Hornet
Image: Ugajin & Colleagues*

Japanese honeybees, Apis cerana japonica, can be attacked by Asian Hornets that raid hives to prey on larvae and pupae. The Asian Hornet has a rigid cuticle that is not penetrated by bee stingers. How is a bee to defend against this threat?

Japanese bees will swarm a hornet and form an attack ball. The bees beat their wing muscles to generate heat. The temperature inside the ball quickly heats the hornet to 47 degrees C, a temperature that kills the hornet but not the bees. The wasp is cooked for about a 20 minute period. This defense evolved in Japanese honeybees that have a long history with the Asian Hornet, but is undeveloped in European Honeybees which are defenseless against Asian Hornets.

*Ugajin A, Kiya T, Kunieda T, Ono M, Yoshida T, Kubo T (2012) Detection of Neural Activity in the Brains of Japanese Honeybee Workers during the Formation of a “Hot Defensive Bee Ball”. PLoS ONE 7(3): e32902.
doi:10.1371/journal.pone.0032902

About jjneal

Jonathan Neal is an Associate Professor of Entomology at Purdue University and author of the textbook, Living With Insects (2010). This blog is a forum to communicate about the intersection of insects with people and policy. This is a personal blog. The opinions and materials posted here are those of the author and are in no way connected with those of my employer.
This entry was posted in behavior, by jjneal, Environment. Bookmark the permalink.

One Response to Turning Up the Heat

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