Asian giant hornet (Vespa mandarinia)

Common Names: Asian giant hornet, murder hornet, Japanese giant hornet

Description:

The northern giant hornet (Vespa mandarinia), formerly called the Asian giant hornet and sometimes sensationalized as the "murder hornet," is the world's largest hornet, native to East and Southeast Asia [2, 5]. A small number were found in Washington State and nearby British Columbia between 2019 and 2021, raising alarm because the hornet can destroy honey bee colonies and deliver a painful, venomous sting [2, 3]. After every known nest was destroyed and no hornets were seen for three years, the United States declared the species eradicated in December 2024 ? so it is not established in North America today, and quick reporting of any suspected sighting is how we keep it that way [3, 4].

Identification:

The northern giant hornet stands out mostly because of its size. Workers run about 1 to 1.5 inches long, and queens reach nearly 2 inches (5 cm) ? far larger than any hornet or wasp native to North America [2, 8]. The head is broad and bright orange-yellow with large dark eyes; the middle section of the body (the thorax) is dark brown; and the abdomen is banded in orange-yellow and dark brown [2]. Its stinger is about a quarter inch (6 mm) long and smooth, so unlike a honey bee it can sting more than once [2].

In its normal life cycle, queens emerge in spring, colonies grow through summer, and new queens and males appear in late October [2]. The hornet is most dangerous to honey bees in late summer and early fall, when groups of hornets attack hives to feed their growing young [2, 3].

At-a-glance cues:

1. Very large ? workers about 1 to 1.5 inches, queens close to 2 inches (5 cm), bigger than any native wasp or hornet [2, 8]
2. Broad, bright orange-yellow head with large dark eyes [2]
3. Dark brown thorax with an orange-and-brown banded abdomen [2]
4. Smooth stinger about a quarter inch (6 mm) long [2]

Hosts:

In its native range across Japan, China, Korea, India, and far-eastern Russia, the northern giant hornet lives in forests and low mountain foothills [2]. It usually nests underground, taking over abandoned rodent burrows or cavities among tree roots, and sometimes nests in hollow or dead trees [2, 4]. A mature nest holds up to a few thousand cells [2]. Workers hunt large insects ? chiefly beetles, other wasps, and honey bees ? and forage up to a mile or more from the nest [2].

The hornet is not native to North America. A handful were detected in Washington State and southwestern British Columbia between 2019 and 2021; every known nest was destroyed, and after three years with no sightings the United States declared it eradicated in December 2024 [3, 4]. There is no established North American population today [3, 4].

Life Cycle:

The northern giant hornet would most likely reach a new area with human help. Mated queens or whole nests can be carried long distances in shipping containers, cargo, soil, potted plants, or untreated wood [7, 8]. Once in an area, new queens also spread on their own by flying to find nesting sites in spring [8].

The hornet lives on a one-year colony cycle. Only mated queens survive the winter, sheltering in the soil for about seven months [2]. In spring a surviving queen comes out, feeds on tree sap, and starts a nest; the colony grows through summer as workers raise more young [2]. In late October the nest produces new queens and males; the new queens mate, and all the other hornets ? including the old queen and the workers ? die off by mid-November [2]. Because only those mated queens carry the population into the next year, finding and destroying nests in late summer or fall, before new queens leave, is the key to stopping it [2, 3].

Impact and Damage:

For people, the main concern is the sting. The northern giant hornet has a large stinger and potent venom, and because the stinger is smooth it can sting repeatedly [2]. In its native range it is a serious hazard: hornet attacks there cause roughly 40 deaths a year, and during one four-month period in China in 2013 they caused 42 deaths and more than 1,600 injuries, usually from multiple stings or allergic reactions [2]. Even so, the hornet is not generally aggressive toward people away from its nest ? most serious stinging happens when a nest is disturbed [2].

The bigger threat is to honey bees and beekeeping. In late summer and fall, a group of just 10 to 20 hornets can carry out a coordinated attack on a hive, decapitating the worker bees and destroying a colony of tens of thousands in a matter of hours ? by some accounts as little as 90 minutes [2, 3]. The hornets then occupy the hive and feed on the bee larvae. European honey bees, the kind kept across North America, have no natural defense, because they did not evolve alongside this hornet [2, 3]. Native Asian honey bees defend themselves by mobbing a hornet in a tight ball and overheating it to about 115 ?F (46 ?C) [2]. Because honey bees pollinate so many crops, an established hornet population would be a serious threat to beekeeping and farming [2, 3].

Similar species:

Several large native insects are mistaken for the northern giant hornet.

The eastern cicada killer (Sphecius speciosus) is the most common mix-up. It is large but still smaller ? about an inch long ? with a narrow, dark head that blends into its body, and uneven pale-yellow marks on the abdomen rather than the hornet's broad, even orange bands. Cicada killers nest alone in the ground and are not aggressive; the males cannot sting at all [9].

The bald-faced hornet (Dolichovespula maculata) is easy to separate by color alone: it is black and white, with a white face, and builds the familiar gray, football-shaped paper nests in trees and on buildings [10].

The European hornet (Vespa crabro) is the only other true hornet in much of North America. It is smaller, more reddish-brown and yellow, with teardrop-shaped marks down the abdomen, and it lacks the giant hornet's wide, solid-orange head [10].

Monitoring and rapid response:

Signs to watch for:

1. Spring through fall: an exceptionally large hornet ? close to 2 inches ? with a broad, bright orange head, near flowers, tree sap, or beehives [2, 8]
2. Late summer and early fall: groups of large hornets attacking a beehive, or piles of headless honey bees at a hive entrance ? a hallmark of an attack [2, 3]
3. Any time: a nest entrance in the ground, in an old rodent burrow, or in a hollow tree, with large hornets coming and going [2, 4]

What you can do:

1. Learn the look-alikes above first ? nearly every "giant hornet" report in North America turns out to be a harmless native insect, so a clear photo prevents needless killing of beneficial species [9, 10]
2. If you believe you have found one, photograph it from a safe distance, note the exact location, and report it right away to your state department of agriculture and through MISIN [3]
3. Do NOT approach, disturb, or try to destroy a nest ? the hornets sting in numbers when defending it, and the risk is serious [2, 3]
4. Beekeepers can protect hives during the fall attack season by fitting entrance reducers or screens that keep hornets out [3]
5. Trained agency crews handle this hornet at the landscape scale: they trap live hornets, tag and track them back to the nest, and destroy the nest at night in protective suits [3, 4]

When to call a professional:

1. Always, for any suspected nest ? never attempt removal yourself; report it to your state department of agriculture [3]
2. If you or someone nearby is stung many times, or has an allergic reaction, seek medical care immediately [2]
3. For chemical control options, contact a licensed applicator or your local cooperative extension office.

Report sightings to MISIN. Help track this species' spread by submitting observations through the MISIN web site or the MISIN mobile app (Android, iOS, Windows, and macOS). Photos at multiple angles paired with a precise GPS location are the most valuable data for confirming new occurrences and triggering rapid-response review.

Credits:

1. GBIF Secretariat. "Vespa mandarinia Smith, 1852." GBIF Backbone Taxonomy. gbif.org/species/5871429
2. University of Florida IFAS, Featured Creatures. "Northern giant hornet, Vespa mandarinia." ask.ifas.ufl.edu
3. Washington State Department of Agriculture. "Northern Giant Hornet" program and eradication announcement. agr.wa.gov/hornets
4. Washington Invasive Species Council. "Northern Giant Hornet" ? detection timeline and eradication. invasivespecies.wa.gov
5. Entomological Society of America (2022). "Northern Giant Hornet Adopted as Common Name for Vespa mandarinia." entsoc.org
6. USDA National Invasive Species Information Center. "Northern Giant Hornet." invasivespeciesinfo.gov
7. Canadian Food Inspection Agency. "Asian giant hornet (Vespa mandarinia)." inspection.canada.ca
8. Washington State University Extension. "Asian giant hornet ? what we know." extension.wsu.edu
9. Alabama Cooperative Extension System. "Cicada Killers: The Asian Giant Hornet Look-Alike." aces.edu
10. University of Maryland Extension. "Social Wasps: Yellowjackets, Hornets, and Paper Wasps." extension.umd.edu

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