When an Asian giant hornet (Vespa mandarinia) scout locates and approaches a Japanese honeybee hive it will emit specific pheromonal hunting signals. When the honeybees detect these pheromones, about one hundred will gather near the entrance of the nest and set up a trap, keeping it open apparently to draw the hornet further into the hive or allow it to enter on its own.[4]
As the hornet enters the nest, a large ball (see image, on the left) of about five hundred honeybees surround it, completely covering it and preventing it from moving.[5] The bees in the ball begin quickly vibrating their flight muscles, raising the internal temperature of the honeybee mass to about 47 °C (117 °F).[5]
Japanese honey bees can tolerate temperatures up to 48 °C (118 °F), and they can generate a temperature of 47 °C (117 °F). The hornet cannot survive more than 46 °C (115 °F), resulting in its death.[4] The level of carbon dioxide also rises within the bee sphere, hastening the hornet's demise. Several bees may perish along with the intruder, but the death of the hornet scout prevents it from summoning reinforcements which could wipe out the colony.[6]
Beekeepers in Japan attempted to introduce the European honeybee in order to increase honey productivity, but European bees lack the same defensive behavior against the hornet as A. c. japonica and the colonies are rapidly destroyed when discovered by the hornets.[4][7]
亚洲蜜蜂离日本近,大概遭遇过侵略,所以有人海战术来对付强大敌人.欧洲蜜蜂没有经验被虐.像白人登陆美洲大陆一样.