David(s) vs Goliath

Anthophila and Vespa . Bees and Hornets. To many people, they mean the same thing: painful stings! But what many of us do not know is, although these two species belong to the suborder of
Apocrita, one is prey to another. The average size of bees can vary from 2.1mm to 39mm, while hornets can grow up till 55mm in length. Judging from their physical sizes, one can almost infer about the predator-prey relationship between these two species. Yes, it is well-known that hornets do attack bee colonies. What are the hornets after? Bee grubs. Simply said, the baby bees, which look like those little, but fat white maggots. The hornets are after food for their own grubs, feeding the bee grubs to those of their own. With just 30 hornets, 30000 bees can be decimated a short time of one hour.

Being attacked by creatures which can grow up to 3 times their size, most would say it is a scene of bee massacre because each bee will defend the nest on its own effort. There is no strategy or team-work whatsoever. Not so for their cousins from the land of the rising sun in Japan.

An intimate frontal view on a hornet’s head

And that of a bee

The Japanese bees have developed a defense-mechanism to deal with hornets. While conventionally, army bees will defend the entrance of the colony in face of an attack by the hornets, the Japanese bees will lure a single hornet which happen to ‘stumble upon’  a particular Japanese Bee nest. They do this by not standing against the hornets at the nest’s entrance, but let the hornet into the nest after the hornet has left its signal at the nest.  Once a hornet is sighted, the Japanese bees will swarm together and use their body language to forward the message to other bees in the nest to prepare for an impending attack.

It is interesting to note that the Japanese bees do not fight the hornet in a “fire against fire” manner. While European bees will stand against hornets and use their stings and jaws to hurt the hornets, the Japanese bees amass themselves around the attacking hornet. They envelope themselves around the hornet in a ball of bees, while vibrating among themselves in order to increase their own body temperatures. In just 15 minutes, the hornet will be ‘roasted to death’ because bees can withstand and upper temperatures limit of 47 degrees Celcius very quickly using their flight muscles, while hornets can only withstand an upper limit temperature of 44-46 degrees Celcius. This also illustrates the significance of working as a team against larger, and stronger predators.

A video below documents this manner of the Japanese bees’ evolved-defense against their natural predators, the hornets.

REFERENCES

Wikipedia – http://en.wikipedia.org/wiki/Asian_giant_hornet (Accessed on 3rd April 2010)

“Bees Battle  ‘Hornets From Hell'”, National Geographic Digital Media, Video in The News  – http://news.nationalgeographic.com/news/2005/10/1012_051012_hornet_video.html (Accessed on 3rd April 2010

“Japanese Bees Swarm Tactics”, YouTube – http://www.youtube.com/watch?v=JtFVQe4JRmA&feature=player_embedded (Accessed on 3rd April 2010)

“Defensive Adaptations” – http://www.bio.davidson.edu/people/midorcas/animalphysiology/websites/2001/Thawley/defense.htm

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