Don’t try this at home: Stings are painful!
“All it takes is one. One enterprising scout to find the honey bee colony. Mark it with a pheromone. Return with a band of natural born killers. And make all hell break lose.” Sounds like the latest Tarantino? Close. It’s the beginning of a National Geographic video that documents the annihilation of 30,000 European honey bees by 30 (yes, 30!) Asian giant hornets. We’ve found out more about these bullies of the insect world.
Got you! Asian giant hornet with two honey bees
Five times bigger than your average European honey bee, the Japanese hornet is one of the insect world’s most feared predators. At 5 cm (2 in) long and with a wingspan of about 7.6 cm (3 in), there are not many insects that can get in its way. Though found throughout Asia, the Japanese hornet, a.k.a Asian giant hornet (Vespa mandarinia), is most common in Japan’s mountainous regions.
They’re huge – and not always this tame
The Japanese hornet’s stinger is about 6 mm (0.25 in) long and able to inject an especially potent venom that can even damage tissue or disintegrate human flesh. A Japanese scientist who got stung described the sensation as feeling “like a hot nail being driven into his leg.” Ouch!
Mincemeat again: Praying mantis victim
If stung by a giant hornet, treatment should follow soon after as even people can die from their stings. Though less toxic than honey bee venom, the Japanese hornets’ toxicity is one of the greatest per sting because of the sheer quantity of venom injected. About 40 people die in Japan every year after being stung, mainly as a result of an allergic reaction to the venom.
Outrunning doesn’t work either as the hornets can fly at speeds of up to 40 km/h (25 mph) and travel distances of 97 km (60 miles) in a single day. Even an impressive predator in its own right like the praying mantis doesn’t stand a chance against the giant Japanese hornet.
Natural born killer: Vespa mandarinia
And the mincemeat comparison is really not far off. Not able to digest protein as such, the Asian giant hornet chews its prey into a fine paste with which it can then feed its larvae. They in turn produce a clear liquid that feeds the adults. Like a well oiled feeding machine.
As far as an attack on a honey bee hive is concerned, the Asian giant hornets’ strategy is simple: find, trace and attack with reinforcements. One hornet can kill about 40 European honeybees per minute – that means a hive of about 30,000 should take 30 hornets only about three hours! Once a hive is emptied, the hornets feast on the honey and carry the bee larvae back to feed their own.
Hornets ain’t hiding from no one
But, the bees are not as defenseless as it seems. Well, the native bees like apis cerana japonica at least. European honey bees were introduced in Japan to increase productivity but with no defense against unknown predators like the giant hornet, whole colonies can be wiped out by just a few dozen giant hornets as seen.
Awesome bee-boying: The bee ball defense
Native bees, however, employ a clever strategy once they spot a hornet scout trying to call reinforcements via its pheromone trail: About a hundred will set a trap near the entrance to the hive, trying to lure the scouting hornet further inside where about 500 honey bees will surround it and suffocate it with their own densely packed bodies. In addition, they quickly vibrate their flight muscles, therefore increasing the temperature to 47 °C (117 °F), knowing well that the hornet cannot survive more than 46 °C (115 °F). The honey bees can barely stand it themselves and a few will die of overheating too but that’s a small sacrifice given what would happen if hornet reinforcements entered the hive…