The sting of the Asian giant hornet is about 6 mm (¼ in) in length, and injects an especially potent venom that contains, like many bee and wasp venoms, acytolytic peptide (specifically, a mastoparan) that can damage tissue by stimulating phospholipase action, in addition to its own intrinsic phospholipase. Masato Ono, an entomologist at Tamagawa University near Tokyo, described the sensation as feeling "like a hot nail being driven into my leg.".
An allergic human stung by the giant hornet may die from an allergic reaction to the venom, but the venom contains a neurotoxin called mandaratoxin which can be lethal even to people who are not allergic if the dose is sufficient. Between 20 and 40 people die each year in Japan after being stung by giant hornets.
A few interesting notes on Vespa mandarinia's venom and stinger:
- The venom contains at least eight distinct chemicals, some of which damage tissue, some of which cause pain, and at least one which has an odor that attracts more hornets to the victim.
- The venom contains 5% acetylcholine, a greater concentration than is present in bee or other wasp venoms. Acetylcholine stimulates the pain nerve fibers, intensifying the pain of the sting.
- Vespa mandarinia uses its large crushing mandibles, rather than its sting, to kill prey.
- The venom of the Asian giant hornet is more toxic than that of most other bees or wasps, giving this species one of the greatest lethal capacities per colony.
- The enzyme in the venom is so strong that it can dissolve human tissue. On some occasions, the sting may be compared to the effects of a spider bite.
- Like all hornets, V. mandarinia has a barbless stinger, allowing it to sting repeatedly.