The Asian giant hornet (AGH) is a social wasp species. Its native range extends from northern India to East Asia. This pest was first reported in the Vancouver Island area of Canada in August 2019 and has since been detected in the far northwest corner of Washington State.
Asian Giant Hornet (Vespa mandarinia), is the world’s largest hornet, measuring up to 2 inches long. Despite its large size and distinctive markings, people often confuse it for other species.
From 1.5 to 2 inches
AGH adults have a “wasp waist” between the thorax and abdomen.
[USDA Photo by Hanna Royals]
Note: The contrast between the head color and the thorax color is much more apparent in AGH than in cicada killers.
[USDA Photo by Hanna Royals]
Note: The contrast between the head color and the thorax color is much more apparent in AGH than in cicada killers.
[USDA Photo by Hanna Royals]
[USDA Photo by Hanna Royals]
[USDA Photo by Hanna Royals]
Note: Does not occur west of the Rocky Mountains.
[USDA Photo by Hanna Royals]
Note: Females may be yellow, more resembling a wasp.
[USDA Photo by Hanna Royals]
Note: Most paper wasps have a well-defined “wasp waist” that separates them from other hornets.
[USDA Photo by Hanna Royals]
[USDA Photo by Hanna Royals]
[USDA Photo by Hanna Royals]
Note: Bumblebees can be separated from wasps and hornets because their bodies are covered in hairs and appear “fuzzy,” and they have a structure for gathering pollen on their hind legs.
[USDA Photo by Hanna Royals]
Spring: A fertilized queen emerges after surviving the winter. She enters a brief pre-nesting stage. The queen feeds on sap, develops her ovaries, and looks for a suitable nesting site. She usually nests in preexisting underground cavities with a narrow opening, such as rodent burrows.
Summer: Once the queen selects a suitable site, she enters a solitary phase. During this time, she alone is responsible for building a nest, foraging, laying eggs, and caring for young. When around 40 workers are in the nest, the colony enters a new phase. The queen becomes completely nest-bound, and the workers assume all duties outside of the nest.
Late Summer/Early Fall: When there are many workers, the colony begins producing males and the next year’s queens. Workers feed these new “reproductives” within the nest because reproductives do not forage. To obtain food with higher protein, AGHs may attack honey bee hives in the late summer/early fall. The hornets kill all of the adult bees and leave them at the bottom of the hive. Then the hornets remove the hive’s brood, taking bee larvae and pupae back to their nests. AGHs may attack other social bees and wasps at this time.
Fall: Males develop and leave the nest before females. They will perch at the entrance of nests waiting to mate with the new queens, which emerge about 1 month later. New queens must mate before overwintering because males will not be present when the queens emerge the following spring.
Winter: After mating, a new queen will spend the colder months overwintering in a sheltered spot she has excavated in the soil, rotting wood, or piles of straw. The cycle begins again the following spring when the new queens emerge from overwintering.
AGH does not attack people unless it feels threatened. An AGH’s stinger is longer than that of bees or wasps found in the United States, and their venom is more toxic. People with an allergy to bee or wasp stings should take particular caution and calmly leave the area if they believe they have sighted an AGH. More information about AGH and human health can be found at https://agr.wa.gov/departments/insects-pests-and-weeds/insects/hornets/human-health.
In Washington State only, people should report potential sightings of the AGH through the Washington State Department of Agriculture’s website. Outside of Washington, contact your state apiary inspector. If it is safe to do so, take a photo or collect a dead specimen of the pest to help experts identify the insect.
All photographs in the “Asian Giant Hornet and Lookalikes” are the products of PPQ’s Identification Technology Program (ITP). Colorado State University’s C. P. Gillette Museum of Arthropod Diversity provided the specimens.
ITP’s pest identification experts use high-technology imaging systems, software, and molecular diagnostics to create a wide array of digital and other identification tools. Visit idtools.org to browse their extensive pest identification resources.
If you are interested in pollinator health, you may find these two ITP identification resources useful: