What is Asian giant hornet and why was it alarming
Vespa mandarinia is the world's largest hornet species, native to East and Southeast Asia. Workers reach 38-45 mm in length — nearly twice the size of a large bald-faced hornet. Queens reach 50 mm. The species is alarming for two reasons: its venom is exceptionally potent (containing mandaratoxin, a paralytic compound not found in other wasp venoms), and it is a mass predator of honey bee colonies. A group of 20-30 V. mandarinia workers can kill an established honey bee colony of 30,000 bees in under 2 hours in what is called a 'slaughter phase' — they decapitate the bees and carry the thoraxes back to the nest as protein food for their larvae. This predation behaviour is devastating to honey bee populations in areas where Asian giant hornets establish.
The first confirmed North American specimen was found in Nanaimo, BC in September 2019. Subsequent detections occurred near Blaine, Washington, and at several additional BC Lower Mainland-adjacent sites through 2021-2022. The BC Ministry of Agriculture and the Washington State Department of Agriculture conducted coordinated eradication programs involving tracking, nest destruction, and intensive monitoring. No confirmed living colonies have been found at any BC or Washington site since November 2022.
2026 status: monitoring, not crisis
The formal BC eradication program concluded in 2022 with a determination that the known populations had been destroyed. Monitoring has continued through 2023-2026 via a network of passive traps deployed across the Lower Mainland and Fraser Valley, supplemented by citizen science reports through iNaturalist and the BC MAFF reporting portal. As of May 2026, no verified V. mandarinia individuals have been reported in BC since the 2022 eradication. This is a positive outcome, but 'no recent detections' is not the same as 'zero risk' — new queens could theoretically be transported via international freight from Asia or could have dispersed further south from the eradicated population than the monitoring perimeter captured. The CFIA's ongoing monitoring reflects appropriate precautionary science rather than active crisis management.
Visual identification: not mistaking European hornets for Asian giant hornets
European hornets (Vespa crabro) have been increasing in the Metro Vancouver area since approximately 2019 — the same period when Asian giant hornet fears were at their peak. This created a wave of misidentification calls. European hornets are genuinely large (25-35 mm), are the only Metro Vancouver wasp that flies actively at night, and are brownish-orange with yellow abdominal banding — not the vivid yellow-and-black of a yellowjacket. They build nests in hollow trees and large attic voids with papery brown envelope structures. They can be alarming in size but are significantly less aggressive than bald-faced hornets and considerably less aggressive than Asian giant hornets.
| Species | Size | Head colour | Body colour | Flies at night? | Status in BC 2026 |
|---|---|---|---|---|---|
| Asian giant hornet (Vespa mandarinia) | 38–50 mm | Bright orange | Brown + yellow-orange bands | Yes | No confirmed presence; report any sighting |
| European hornet (Vespa crabro) | 25–35 mm | Brownish-red to tan | Brown + yellow bands | Yes | Established in Lower Mainland |
| Bald-faced hornet (Dolichovespula maculata) | 18–25 mm | Black + white | Black + white | No | Common across BC |
| Yellowjacket queen (Vespula spp.) | 15–20 mm | Black + yellow | Black + yellow | No | Very common across BC |
Climate context: why monitoring continues
Asian giant hornets are native to temperate and subtropical Asia, including northern Japan and northern China where winter temperatures can drop below -10°C. This means BC's climate is not inherently inhospitable to the species — unlike many tropical pest species that can't survive coastal BC winters. The successful eradication of the 2019-2022 detected population was partly a function of speed: the known populations were small enough to track and destroy before they could expand. Had the population been discovered 3-4 years later, eradication would have been significantly more difficult. The ongoing monitoring reflects the scientific recognition that undetected introductions are always possible through international trade and shipping.
What to do if you encounter or suspect Asian giant hornet
- Do not approach or attempt to remove. V. mandarinia is significantly more dangerous per sting than any other wasp in BC — the venom volume per sting is 10x that of a honey bee.
- Photograph from a safe distance (phone zoom) — a clear photo with size reference (coin, ruler) is far more useful to authorities than a description.
- Report immediately to the BC Ministry of Agriculture, Food and Fisheries through the online pest report portal at agri.gov.bc.ca/cropprot/pestdisease. They respond to AGH reports within 24 hours.
- Note the GPS location and time of sighting. If the hornet was foraging, try to note the direction it flew when it departed.
- Do not call local pest control as a first response — this is a reportable pest under the BC Plant Protection Act, and the Ministry's tracking protocol supersedes standard pest management.