Thirty giant hornets can destroy a colony of 30,000 honeybees in just 3 hours. The giant hornet is five times the size of the European honeybee, and has a very potent venom.While they can be dangerous, they are not normally aggressive unless threatened.

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• Wikipedia: Bee, Hornet, Japanese giant hornet

Original description:
Giant Japanese hornets slaughter European honeybee hive. From National Geographic. - - - - - -On Japanese Honeybee defense: Ono, M., Igarashi, T., Ohno, E., ...