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Monday, April 2, 2012

Japanese Bee's Ball of Heat Kills Hornets

After my friend and fellow blogger Mike Rogers wrote about the Japanese bee, and discovered that it wasn`t just Japanese bees - it was bees all over the world.

Mike`s article in his Marketing Japan blog back on March 26, 2012, was fantastic - read it HERE.

Anyhow... I saw a science piece on the Japanese bee recently that showed how it gets rid of an aggressive enemy with some controlled mob mentality and some efficient use of heat energy.

In a change of pace, rather than Japan invading Asia (like it liked to do back in the 1930s+, a nasty piece of work called the Asian Hornet likes to invade the air space of the Japanese honeybee (Apis cerana japonica).

The Asian hornet is the world's largest hornet. It lives in the temperate to tropical parts of East Asia. With a body length of 50mm (about two inches), it has a wingspan of 76 mm (three inches) and packs a nasty looking six mm (0.2 inch) stinger that can inject a large amount of portent venom. That sting has been described akin to having a large nail being driven into one's leg. Owtch!

While the venom can be lethal to those who are allergic to bee stings, the Asian Hornet can also kill those who are not allergic... it's that powerful... so perhaps it's good that the Japanese bumblebee has figured out a away to kill the buggers.

Check out the photo above. That`s a swarm of Japanese honeybees cooking an Asian Hornet within what scientist call a `hot defensive bee ball`.

This is not something that other bees do. This is pretty much unique to the species.

When a hornet scout approaches a Japanese honeybee hive, it emits pheromonal hunting signals. When the honey bees detect these pheromone, they begin to swarm around the hornet... but not merely just around it... around 500 of them will form a ball around it to prevent it from moving.

The honeybees will then begin to vibrate their flight muscles, which heats up the air within the bee ball... going up to 46C (115F).

As well, the ball of bees will raise the levels of carbon dioxide (CO2) around the hornet.

Thanks to the levels of carbon dioxide, the honeybees themselves can handle a temperature of up to 50C (122F), but the hornet cannot .

The combination of carbon dioxide levels and the high heat will kill the Asian hornet.

That temperature of 46C - when reached - can be held by the bumble bees for up to 20 minutes, though the hornet will remain within the bee ball for about 60 minutes, which is how long it will take to die.

While not a newly observed phenomenon, how it was done was a mystery.

Scientists at the University of Tokyo have been looking at the brains of bees and have determined that neural activity in the bee brain increases as the attack picks up in intensity

The scientists were also astounded to realize that while the Japanese honeybees are able to generate enough heat to kill the hornet, the bees themselves were mostly unaffected - but often a few will die during the process.

Another pleasant surprise was the the bees used a coordinated attack, implying teamwork.

The hot defensive bee ball manoeuvre appears to have evolved as a means to combat the Asian hornet because its stinger is not strong enough to pierce the dense hornet exoskeleton.

By killing the Asian hornet scout, the bees prevent a signal from the hornet going back to its swarm - thus the Japanese honeybee hive remains safe.

You can see the bee ball in action HERE

Nature is friggin' awesome! 

Man... why do I feel like eating some honey?

By Andrew Joseph


  1. Hey, I've seen those hornets before. They are some mean-looking critters and, as you wrote, huge! Their orange color makes them even more bad-ass looking.

  2. Last summer we had a hive of some sort of blue wasp... living with their yellow striped cousins in equal numbers inside the walls of our house - and then in an outside box for the digital TV etc. hook-up.
    They weren't overly aggressive - just huge... about an inch and a half... I had never seen that colour on a wasp before... like where the hell did that come from? I effin' hate bugs. Maybe because I was bitten twice by yer std house spider and had bad reactions... swelling et al... and no cool Peter Parker-like powers. I also once killed a foot-long centipede in my bedroom when I was a teenager... I just believe nature should live outside... and not in my house. It'll never happen of course, but I hate bugs nonetheless.