Identification
Le frelon européen est souvent craint en raison de sa taille, mais il est généralement moins agressif que les guêpes Vespula et n'attaque pas sans raison.
Less aggressive than you might think
Contrary to its reputation, Vespa crabro rarely attacks without direct provocation; it is far less reactive than V. maculifrons around food sources.
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AImposing size
The largest Vespidae species in Quebec; queen up to 35 mm, workers 18-24 mm; noticeably larger than the yellowjackets (Vespula); audible flight.
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BDistinctive colouring
Rusty brown on the head, thorax and upper abdomen; yellow and black bands on the abdomen; no bright yellow, unlike Vespula.
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CNocturnal behaviour
Active at night, unlike every other wasp in Quebec; strongly drawn to light sources (streetlights, lit windows) in summer.
Worker
Hunts insects, larvae and even small vertebrates; strips the bark of fruit tree branches to harvest the sap; defends the nest vigorously if approached.
Life cycle
From the spring founding to the autumn die-offThe overwintering queen emerges in May and chooses a hollow tree cavity, an attic or a space in an old building to begin building the nest.
The workers enlarge the papier-mâché nest; the colony reaches 200 to 400 individuals at its peak in August; activity is both diurnal AND nocturnal.
In August and September, males and new queens are produced; mating takes place in flight; the new queens look for overwintering sites in the ground or under bark.
Frost kills the workers and males in October and November; the nest is abandoned and never reused; only mated queens survive in hibernation.
Not to be confused with
Its large size and rusty brown colouring clearly set it apart from the yellowjackets.
Asian hornet
Yellow legs and a velvety black thorax; not established in Quebec but under surveillance.
Bald-faced hornet
Much smaller (13 to 20 mm), black and white, with a large ball-shaped aerial nest.
Signs of activity
Nest in a tree cavity or attic
A large oval brown-grey papier-mâché nest in a hollow tree, an old wall, an attic or a barn; wide entrance (4-8 cm); audible buzzing at night.
Damage to fruit trees
Bark stripped from lilac, apple or ash branches to harvest the sap; strips of missing bark at waist height on young branches.
Night-time activity around lights
Workers drawn to lit windows and streetlights in July and August; the only wasp species in Quebec that is active at night.
Despite its reputation, the European hornet is less aggressive than yellowjackets away from the nest; stings are painful but deliver no more venom than a Vespula sting.
Treatment
Reducing night-time attraction
- 1 Insect glue tape A passive trap placed near light sources
- 1 Warm white LED bulbs Less attractive than fluorescent tubes or cool white LEDs
- 1 Window screens Keeping them from getting into the house at night
- Replace the outdoor bulbs with warm white or orange LEDs, which are less attractive to nocturnal insects.
- Keep windows closed or fitted with screens on summer nights to avoid accidental entries.
- If a hornet gets into the house, turn off all the indoor lights and light up an open window to guide it back outside.
A lone hornet flying around you is drawn by warmth or odours; stay still and it will move on. Sudden movements and swatting trigger a defensive response.
A hornet nest found in autumn or winter is empty and harmless; it can be removed by hand with gloves. Nests are never reused from one year to the next.
Locating and assessing the nest
Observing both night-time and daytime behaviour
If you hear loud buzzing at night or see large insects drawn to your lights, look for a nest in a hollow tree or a nearby structure.
Look for a large brown paper structure in tree cavities, attics or old buildings; the entrance is wider than a Vespula entrance (4-8 cm).
A nest in a tree away from areas of human activity can be tolerated; a nest in an occupied building or less than 5 m from a busy walkway warrants a consultation.
Prevention
- Seal building cavities
Plug the gaps under roofing, the voids in stud walls and attic openings before May to discourage founding queens from moving in.
Building - Turn off unnecessary outdoor lights
Bright outdoor lights attract hornets from July onward; use timers or motion sensors to limit night-time lighting.
Outdoors - Protect fruit trees
Apply a sticky repellent to the branches of young fruit trees to discourage workers from stripping bark in search of sap.
Garden
Frequently asked questions
Is the European hornet dangerous?
Impressive because of its size but not very aggressive away from the nest. Its sting is painful and risky for people with allergies; it defends its colony fiercely.
Where does it build its nest?
In a cavity: a hollow tree, an attic, a wall or a shed. The brown paper nest can grow quite large by the end of the summer.
How do I recognize it?
A large reddish brown and yellow wasp (Vespa crabro), much bigger than a common wasp; it sometimes flies in the evening, drawn to light.
How do I get rid of a nest?
Given its size and how it defends the nest, do not attempt anything yourself. An exterminator treats the nest in the evening with the required protective equipment.