The Northern Giant Hornet (Vespa mandarinia), formerly known as the Asian Giant Hornet, is the world’s largest hornet species, measuring up to two inches in length. This insect garnered significant media attention due to its size and aggressive predatory behavior against honeybee colonies. Its initial detection in North America prompted widespread concern over its potential impact on agriculture and native ecosystems.
Current Status of the Northern Giant Hornet in the US
The Northern Giant Hornet is currently considered eradicated from the United States, a status officially declared by the Washington State Department of Agriculture (WSDA) and the United States Department of Agriculture (USDA) in December 2024. This declaration followed three consecutive years without confirmed detections, meeting the scientific threshold for successful eradication. The initial confirmed sighting occurred in December 2019 in Whatcom County, Washington state, near the Canadian border. Authorities concentrated all subsequent eradication efforts in this area, successfully locating and destroying four nests: one in 2020 and three during 2021. The hornets were found nesting in tree cavities and other protected spaces.
Distinguishing the Northern Giant Hornet
Accurate identification is important to avoid misidentifying native insects. Worker hornets measure between 1.5 and 2 inches in length, making them noticeably larger than most other wasps in North America. A primary distinguishing feature is the hornet’s massive head, which is a prominent orange or orangish-yellow color, contrasting sharply with the rest of its body. The abdomen displays alternating bands of yellow, black, and reddish-brown coloration.
This pattern helps differentiate it from look-alike species such as the European Hornet (Vespa crabro), which is smaller (1 to 1.5 inches) and has a reddish-brown thorax and head. European Hornet abdominal bands feature black, teardrop-shaped markings. Northern Giant Hornets consistently build their nests underground, while European Hornets typically construct their paper nests in protected aerial locations.
Impact on Honeybee Populations
The primary threat posed by the Northern Giant Hornet stems from its specialized predatory behavior toward social insects, particularly the European honeybee (Apis mellifera). Hornet attacks escalate into the “slaughter phase,” where a small group of hornets (20 to 30 individuals) can decimate a colony of thousands of bees in just a few hours. The hornets swiftly kill adult bees by decapitation. Following this destruction, the hornets enter the “occupation phase,” systematically harvesting the protein-rich bee larvae and pupae from the brood comb to feed their developing young. Such attacks pose a direct threat to the beekeeping industry, which supports the pollination of agricultural crops across the US.
How to Report Potential Sightings
Although the Northern Giant Hornet has been declared eradicated, public vigilance remains important, as the insect could potentially be reintroduced. If a large, suspicious insect is encountered, prioritize safety and refrain from approaching or attempting to kill it, as the hornet can sting multiple times. The most effective step is to immediately document the sighting with clear photographs or video footage.
Reports should be submitted to the state’s department of agriculture or a local extension office. Washington residents should direct reports to the Washington State Department of Agriculture (WSDA). Crucial information to include is the exact location, the date, and the time of the sighting, along with any visual evidence.