Recent news reports tell of the deadly Asian hornets making soon making their way to the East Coast in America. The meat-eating flying insects have been first detected in Washington in December of last year.
The hornets are blamed for killing at least 50 people a year in Japan. The New York Times reports that they can go through a hive and kill a bee every 14 seconds.
However, researchers have discovered a contender in fighting the deadly hornet: the Japanese honeybee. When grouped, experts have learned that the bees form a ball and trap the hornet inside it.
The bees then start to vibrate and produce heat, somewhat 'cooking' the hornet. Japanese bees are said to endure high temperatures, and after an hour, can kill the hornet using their 'thermal bee ball' technique.
European honeybees, which are also found in the US, have been observed to attempt to sting the hornet. However, due to the tough exoskeleton of the insect, the bees' efforts were ineffective. According to a researcher, the Japanese honeybee learned to tailor its tactic through generations.
Why do Hornets Target Beehives?
In case you were wondering why a hornet would go in harm's way and attack a hive full of bees, it's because they have mouths to feed. Giant hornets feed their larvae with protein from carcasses of the larvae of other insects.
Honeybee hives are not only filled with honey and pollen but also contain honeybee larvae. Therefore, the hornets enter beehives targeting to get their larvae.
Notorious for being vicious killers, the Asian hornets use their sharp talons and strong mandibles to rip through hives and cut out the limbs and heads of the bees. European honeybees are helpless against the atrocious predators.
Correspondingly, European honeybee hives are rapidly annihilated by the hornets. The hornets then chew the honey bee larvae into protein paste to serve to their own young hornet larvae back in their nests.
The Japanese Bee Ball Oven
A group of Japanese scientists studied the honeybees' genetic code and brain structure. In their study published in the journal PLOS ONE, the team found that at least one immediate early gene became much more active within the brains of Japanese honeybees compared with those of European bees.
According to Wulfi Gronenberg, a neuroscientist at the University of Arizona, this part of the bee's brain is a large area involved in learning, memory, and processing light. He added that this is also where the bees keep their sensory cues.
Not like the European honey bee, the Japanese honey bee has a specific defensive mechanism in response to the predator, the hornet. Their behavior involves swarming the hornet and then enclosing it into a ball.
The swarming and the quivering muscle fibers from the bees raise the temperature of the ball's interior to 117ºF, a temperature deadly to the hornet, but not to the bees. The hornet is then killed from overexposure to heat.
Through this defense tactic, the Japanese honey bees can save their hive. The National Geographic describes it as an incredible group defense mechanism.