Identification
The common yellowjacket is a yellowjacket wasp that hunts insects and gathers carbohydrates (nectar, fruit). It closely resembles the European common wasp, of which it was long considered a synonym.
A populous colony
By late summer, a yellowjacket nest can hold thousands of workers; the common yellowjacket usually nests in the ground.
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AAbdomen
Alternating yellow and black bands; the stinger does not stay stuck in the skin, so the wasp can sting several times.
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BHead
The female's clypeus (lower face) usually bears a central black mark that widens toward the bottom, shaped like an anchor or a dagger; the German yellowjacket instead has three small black dots.
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CWings
Two pairs of membranous wings; at rest, they are folded lengthwise, as in other wasps of the family Vespidae.
Worker
Builds the cells, hunts insects, collects sugars and defends the nest.
Life cycle
From the new nest to the colony's autumn breakdownA queen that has overwintered comes out of dormancy in spring, chooses a cavity (burrow, stump, wall void) and founds the nest on her own.
The first workers appear in early summer and take over the work of the nest; at the height of the season, the colony can number several thousand individuals.
In late summer, the colony produces males and new queens; the wasps are very common at food sources.
In autumn, the colony collapses; only fertilized queens spend the winter in shelter and found a new nest in spring (the old nest is generally not reused).
Not to be confused with
Several Vespula species share a very similar yellow-and-black striped pattern.
Signs of activity
Underground or cavity nest
Nest usually in the ground, sometimes in a rodent burrow, a stump, a wall void or an attic.
Intense activity in late summer
Large numbers around garbage cans, meat, sweet drinks and fallen fruit in late summer.
Patrol flights
Steady coming and going of workers around a single spot; defensive behaviour if you approach the nest entrance.
In late summer, the colony is at its peak and the wasps are more common around food. Avoid disturbing an active nest.
Treatment
Homemade sugar trap
- 1 L Water Liquid base
- 4 tbsp Sugar or fruit juice Sweet bait
- 1 tsp Cider vinegar Optional ingredient
- Mix the water, sugar (or juice) and vinegar in a narrow-necked bottle.
- Place the trap at the edge of the yard, away from eating areas, to draw the wasps away from your guests.
- Check the trap regularly, then empty and refill it as needed.
Floral perfumes and brightly coloured or flower-patterned clothing attract wasps. Wear neutral colours and avoid perfume during outdoor activities.
A crushed worker releases alarm pheromones that can trigger a collective aggressive response from the other members of the nest.
Locate and assess the nest
Methodical observation to pinpoint the exact location
From a distance, watch the flight paths close to the ground or along the walls; the workers fly straight in and out through a single spot, the nest entrance.
The entrance is usually a small opening in the ground; it can also be in a foundation crack or under the exterior siding, which points to a nest inside the wall. Spot it from a distance, without approaching.
A nest near a door, a walkway or a lawn that needs mowing, or hidden in a wall, calls for more caution; a nest away from activity areas can often be left in place until autumn.
Prevention
- Sealing entry points
In early spring, before queens look for a nest site, seal foundation cracks, crawl spaces and siding openings with caulk or polyurethane foam. Never plug the entrance of an active nest.
Foundation - Waste management
Use tightly sealed garbage cans and rinse sugary containers before throwing them out. Food waste and sweet drinks attract wasps in late summer.
Yard - Spring inspection
Inspect the perimeter in spring and early summer: a nest found early, before the workers become numerous, is easier to treat.
Outdoors
Frequently asked questions
Is the common yellowjacket aggressive?
It becomes aggressive near its nest and in late summer, when it hovers around food and sweet drinks. It can sting several times.
Where does it nest?
Most often in the ground, sometimes in a stump, a wall void or an attic. The nest entrance is a small opening with heavy worker traffic.
Why is it hovering around my deck?
Late in the season, it looks for sugars and proteins: fruit, drinks, meat. Colonies are then at their peak population.
How do I get rid of a nest?
Locate the entrance without plugging it, keep your distance and call in an exterminator, especially if the nest is in a wall or near a walkway. For help suited to your situation, see our wasp and hornet extermination service.