Invertebrates
Asian Giant Hornet
Vespa mandarinia · also called northern giant hornet, Japanese giant hornet, murder hornet
The Asian giant hornet is the largest hornet on Earth and one of the most formidable insect predators — a fingernail-long wasp with jaws like tin-snips that hunts other social insects and can dismantle a honeybee colony in an afternoon. A short-lived scare over its arrival in North America gave it the tabloid name “murder hornet.”
Overview
The species is native to East and Southeast Asia, in low mountains and forest rather than open plains. Colonies are founded each spring by a single queen, who digs a nest in a rotted root cavity or an abandoned rodent burrow and raises the first workers; the nest grows through summer and produces new queens and males in autumn, then dies, with only mated queens overwintering.
The hive raid
Through most of the year the hornets hunt insects individually, chewing them into a paste to feed their larvae (adults cannot eat solid food and live on sugars and on a nutritious fluid the larvae give back). In late summer, as their brood peaks, they turn to mass attacks on honeybee and other hornet nests. A scout marks the target hive with a pheromone; a squad of 10 to 30 hornets then assaults the entrance and beheads the defenders one by one. A few hornets can kill 30,000 bees, and the raiders then hold the hive and ferry the bee brood home.
Native versus introduced bees
The Japanese honeybee has a defence: it engulfs a scout hornet in a “bee ball” and vibrates to raise the temperature to about 46 °C, killing the hornet before it can call in the raid. The European honeybee, used in most of the world’s beekeeping, has no such behaviour and is essentially defenceless — which is why the hornet’s spread alarms beekeepers.
Danger to people
A sting is large, very painful, and repeatable, and the venom is both toxic to tissue and able to recruit more attackers. Near a nest, victims can receive dozens of stings. In Japan the hornet causes roughly 30–50 deaths a year, mostly from anaphylaxis or, after heavy stinging, kidney failure. Away from a nest, a single sting is not usually dangerous to a non-allergic person.
The North American episode
Asian giant hornets were detected in British Columbia and Washington State from 2019. A large trapping and nest-destruction effort followed; no hornets were confirmed after 2021, and the species was declared eradicated from the region in 2024, with monitoring ongoing.
Status
Vespa mandarinia has not been assessed by the IUCN. It is common within its native range and is not considered at risk there.
Asian Giant Hornet: common questions
Is the "murder hornet" actually a threat to people?
The nickname is sensational, but the danger is real in context. A single sting is intensely painful and delivers more venom than a bee or a smaller wasp, and the venom contains a tissue-damaging component and a chemical that can trigger the release of more venom-attractant, so disturbing a nest can bring a swarm. In Japan, where people and hornets overlap a lot, the species kills roughly 30 to 50 people a year, usually through allergic reaction or, after many stings, kidney failure. For someone not allergic and not near a nest, an isolated encounter is painful but not life-threatening.
Why is it so dangerous to honeybees?
In late summer the hornets switch to raiding social insect nests to feed their own growing larvae. A scout finds a honeybee hive and marks it with a pheromone; nestmates home in on that scent, and a group of a dozen or more hornets then attacks the entrance, biting the heads off adult bees one after another. A handful of hornets can kill tens of thousands of bees in a few hours, after which they occupy the hive and carry the bee larvae and pupae back to their own nest as food. Introduced European honeybees have no effective defence.
How do Japanese honeybees fight back?
The native Japanese honeybee has co-evolved with the hornet and has a striking counter-attack. When a scout hornet enters the hive, hundreds of bees pile onto it in a tight ball and vibrate their flight muscles to generate heat. The centre of the ball reaches about 46°C and builds up carbon dioxide — conditions the bees can just survive but the hornet cannot. The scout is cooked to death before it can summon the raiding party, which often saves the colony.
What happened with the murder hornets in North America?
Asian giant hornets were found in British Columbia and Washington State starting in 2019, raising fears they could establish and harm beekeeping and native pollinators. Agencies ran an intensive trapping, tracking, and nest-destruction campaign, located and eliminated several nests, and found no confirmed specimens after 2021. In 2024 the US and Canada declared the species eradicated from the region, though monitoring continues.