Asian giant hornet

Identification & Biology
Alias' : Asian hornet, Japanese giant hornet
Latin Name : Vespa mandarinia
Category : Insects & Spiders
Description :
  • Large hornet with noticeably large, orange head and black eyes
  • Black and dull yellow/orange striped abdomen
  • Worker hornets are approximately 3.5 cm in length and queens can be up to 4-5 cm in length with a wingspan of 4-7 cm

 

The Asian giant hornet is the world’s largest species of hornet. It is invasive to North America and is classified as a new pest of concern in British Columbia. Asian giant hornets nest in the ground of forested areas, unlike other species of wasps or bees that build nests in trees and/or buildings. They establish annual nests in the spring, and during the summer the nest expands until August when virgin queens will emerge.  After mating, the young queens will disperse and winter on their own. The original nest dies in the fall. Asian giant hornets predate on other large insects for food, and will forage as far as eight kilometers from their nests. They commonly feed on honeybees, and are capable of destroying hives in a short time period. Asian giant hornets are not generally interested in in humans, pets, or large animals, and will only attack when threatened. Their stinger is longer than that of a honeybees and their venom is toxic.

There are several large insects that are native to British Columbia that are commonly seen and could be mistaken for Asian hornets. These include the bald faced hornet, the yellow jacket, the horntail wasp, and the elm sawfly. Asian giant hornets can be distinguished by their large size (~3.5 cm in length) and large, yellow to orange head with black eyes.

Look Alikes
Habitat

Asian giant hornets are widely distributed in East Asia from the sub-tropics of South China to the temperate zones of the Korean peninsula and northern Japan. Nests are commonly found in forested areas in the ground, often in pre-existing underground cavities such as rodent burrows and hollowed trunks. The first report of Asian giant hornet in North America was in August 2019 on Vancouver Island, British Columbia. Shortly after, another individual hornet was reported for the first time in Washington, USA in December 2019. Despite their introduction, they do not yet have established populations. There is no evidence of the Asian hornet being found in other provinces and states in North America.

Impact & Risks
  • Asian giant hornets are a serious concern for honeybees and other native pollinators. They aggressively attack honeybees and a small group of them can destroy an entire colony.
  • They are a potential human health concern as their stinger venom is very toxic and can cause allergic reactions. However, they will only attack if threatened.
  • While Asian giant hornets primarily feed on honeybees and other insects, they have also been known to eat soft fruit. This could result in impacts to the soft fruit industry.
Prevention & Mitigation
  • Governments in British Columbia and Washington state are working with the Canadian Food Inspection Agency and the United States Department of Agriculture to conduct surveillance and to eradicate any potential populations of Asian giant hornet nests.
  • Beekeepers in the Lower Mainland of British Columbia are being encouraged to use screens or barriers as a precaution to protect their bee hives.
  • Government researchers have placed traps in key areas to capture live adult hornets. When live adults are caught, they are attached with radio tags, released, and followed, so experts can potentially locate other nests.
  • Be on the lookout for Asian giant hornets. If you see a suspect hornet, do not destroy the body of the insect. If possible, take a picture and immediately report it to the Invasive Species council of British Columbia at 1-888-933-3722, online, or on the council’s Report Invasives mobile phone app.
  • If you are stung by an Asian giant hornet, place an ice cube/pack or cold compress on the location to reduce inflammation and the spread of venom. Don’t rub the site, it will cause the venom to spread into the surrounding tissue. If you are stung multiple times or have symptoms of a toxic or allergic reaction, seek medical attention immediately.

 

Information primarily sourced from BC Ministry of Agriculture and Washington State Department of Agriculture.

Okanagan Distribution

Priority Level Definitions

Watch For - Poses a significant threat (very high risk) and does NOT presently occur in the region OR is relatively new to the region and is very limited in extent.
High - High risk/impact; limited population with significant potential to spread in the region.
Medium - Medium risk/impact; limited distribution – broader population distribution with potential to spread further in a region.
Low - Low risk/impact; may be widespread or not, may be of concern in specific situations with certain high values – e.g. specific agriculture crops. Some species may be treated primarily with biological control agents.