Insect · High risk
Yellowjacket
In Quebec, “yellowjacket” is the everyday name for the yellow and black wasps of the genus Vespula, and the German yellowjacket (Vespula germanica) is one of the most common around buildings. It builds its papier-mâché nest in the ground or in a cavity of the building and defends it fiercely. Its stings can cause severe allergic reactions.
Worker 12 to 16 mm · Yellow and black
§1Distinctive features
How to identify it
Workers measure 12 to 16 mm, queens up to 18 mm. The body is covered with well-defined yellow and black bands and is hairless, unlike the bee, which is fuzzy. Fast, jerky flight and a narrow waist. The markings on the face and abdomen are the only reliable way to tell Vespula species apart.
§2Habitat
Where to find it
It nests in the ground, under decks, in attics, crawl spaces and wall cavities. The grey-brown papier-mâché nests often reach the size of a basketball and can hold up to 15,000 cells.
§3Reproduction
Lifecycle
From July to September, the colony grows quickly in just a few weeks, and the nest becomes much riskier to remove.
§4What to look out for
Signs of an active nest
- Heavy wasp traffic toward an entrance
- Visible greyish papier-mâché nest
- Stings during outdoor activities
- Wasps around sweet food on the patio
§5Why act fast
Risks
- Painful stings that can cause anaphylactic reactions
- Extreme aggressiveness if the nest is disturbed
- Multiple stings possible (the stinger does not tear off)
- A danger for children and people with allergies
§6Prevention
How to avoid it
- Inspect attics and foundations in spring
- Seal gaps and cavities in spring or after the frosts, never in front of an active nest
- Do not leave sweet drinks open on the patio
- Call a professional if you find a nest
§7Pro method
How MW works
Inspection
Locating the nest and assessing the sting risk.
Preparation
Intervention plan · safety perimeter and time window.
Treatment
Treating the nest and its entrance with an insecticide dust, then physically removing the nest.
Follow-up
Control visit for returning foragers · written guarantee offered depending on the treatment chosen.
§8Your questions answered
Frequently asked questions
Should the nest be destroyed?
Does a wasp die after stinging?
When are nests most dangerous?
Yellowjackets turn aggressive in late summer, when food becomes scarce. That is when calls go up, especially in Sherbrooke, Granby, Saint-Hyacinthe and Drummondville. Our nest removal service is available 7 days a week.
Sources consulted for this fact sheet: Office québécois de la langue française, guêpe jaune · Espace pour la vie, social wasps in Quebec · Cornell University IPM, yellowjackets · UC IPM, yellowjackets and other social wasps.
Act before the nest gets bigger.
The bigger the nest, the riskier and costlier the removal.