Insect · High risk
Bald-faced Hornet
The bald-faced hornet is one of the largest wasps in Quebec. Its black colouring with ivory white markings sets it apart from other species at a glance. It builds large aerial nests and is considered one of the most aggressive wasps in North America.
13 to 20 mm · Black and white
§1Distinctive features
How to identify it
A large black wasp marked with ivory white on the face, thorax and tip of the abdomen: workers measure 13 to 18 mm, the queen up to 20 mm. Despite its English name, the bald-faced hornet is not a true hornet but a wasp of the genus Dolichovespula. Its nest is unmistakable: a pear-shaped envelope of mottled grey paper hanging in a tree or shrub, up to 35 cm across and 60 cm tall.
§2Habitat
Where to find it
It hangs its nest in trees and shrubs, most often 1 to 18 m off the ground, sometimes under eaves, a balcony or a bridge. It prefers wooded areas and gardens with dense vegetation. Adults feed on nectar, sap and ripe fruit, but they hunt flies, caterpillars and spiders to feed the larvae: away from the nest, it is a useful predator.
§3Reproduction
Lifecycle
The nest grows fast: the size of a golf ball in June, it can be bigger than a basketball by August.
§4What to look out for
Signs of an active nest
- Large pear-shaped grey paper nest hanging in a tree
- Black and white wasps in flight
- Intense aggressiveness when you approach the nest
- Loud buzzing around the nest
§5Why act fast
Risks
- Smooth stinger: each wasp can sting several times in a row
- Severe allergic reactions that can be fatal
- Venom sprayed toward intruders' eyes: intense irritation and blurred vision
§6Prevention
How to avoid it
- Never approach the nest
- Inspect trees and shrubs from late spring, while the nest is still small
- Call a professional right away
- Wear full protection when working nearby
§7Pro method
How MW works
Inspection
Locating the nest, assessing the height and access.
Preparation
Intervention plan · safety perimeter and full protection.
Treatment
Neutralizing the nest by injecting directly into the opening, then removing the entire envelope.
Follow-up
Control visit · written guarantee offered depending on the treatment chosen.
§8Your questions answered
Frequently asked questions
How is it different from the eastern yellowjacket?
Can they sense fear?
Can an empty nest be kept in winter?
Never remove a bald-faced hornet nest yourself: the workers pour out as soon as someone comes within a metre, and a nest perched five or ten metres up means working at height under attack. Our wasp nest removal service comes the same day. In Granby, nests high up in mature maples are common; in Sherbrooke, they are found mostly in the wooded areas of Vieux-Nord and Rock Forest, and the picture is the same in Magog and Bromont.
Sources consulted for this fact sheet: Québec.ca, hornets, wasps and bees · Espace pour la vie, social wasps · Office québécois de la langue française, guêpe à taches blanches · Penn State Extension, baldfaced hornet.
React quickly, sleep well.
The bigger the nest, the riskier the intervention.