Identification
Le nid de la guêpe à taches blanches est l'une des constructions les plus élaborées du règne animal: une architecture de papier mâché à plusieurs couches isolantes.
Remarkable architecture
The nest can hold up to 700 individuals and stand 60 cm tall; its smooth outer surface protects the colony from predators and from the weather.
-
AColouring
Matte black body marked with large ivory-white patches on the face, the thorax and the abdomen; a unique pattern that makes field identification easy.
-
BNest
Grey papier-mâché aerial nest, egg-shaped, able to reach 30-60 cm; built from chewed wood fibres mixed with saliva.
-
CStinger
Smooth stinger allowing repeated stings; releases venom with every sting and can spray venom toward the eyes in cases of extreme danger.
Worker
Larger than the other wasps of the genus Vespula, it is known for defending the nest vigorously and can chase an intruder for several metres.
Life cycle
From early spring to the first autumn frostThe overwintering queen comes out in May, chooses an aerial site (branch, eave) and starts building the papier-mâché nest.
The workers enlarge the nest steadily; the colony can reach 400 to 700 individuals at its peak in August.
In late August, males and new queens are produced; the young mated queens leave to find a site to overwinter in.
Frost kills the workers and males in October; the empty nest is never reused; the queens overwinter in the soil or under bark.
Do not confuse it with
Its black and white colouring sets it apart from the other yellow and black wasps.
European hornet
Much larger (up to 35 mm), brown and yellow, nests in cavities.
Paper wasp
Slender, legs dangling in flight, open comb nest with no envelope.
Signs of activity
Visible aerial nest
A large greyish balloon-shaped structure hanging from a tree, a dense hedge, an eave or a metal structure; the entrance hole is at the bottom of the nest.
Aggressive defence
The workers actively patrol 1-3 m around the nest and attack with no apparent provocation if you come too close; they can sting several times.
Chewing activity
You may hear a faint scraping sound as the workers gather wood fibres from fences, railings or dead wood to build the nest.
Never try to remove an active nest yourself; the entire colony can attack at once.
Treatment
Identification from a distance
- 1 Pair of binoculars Observe the nest without approaching
- 1 Camera (zoom) Photograph the nest for assessment
- 1 Marking tape Mark off a safety perimeter
- Observe the nest from at least 5 m away with the binoculars to assess its size and its activity.
- Photograph the nest to document its location and share it with a professional if needed.
- Mark off a safety perimeter around the nest to warn passers-by and pets.
Any vibration or spray of water triggers an immediate defensive response from the whole colony. This species is especially reactive to disturbance.
A nest found in winter or early spring is empty and can be removed safely. Nests are never reused the following year.
Assessing the nest safely
An observation protocol from a distance
Look for a greyish egg-shaped mass in trees, hedges or under eaves; the nest is more visible after the leaves fall in autumn.
Assess the distance between the nest and busy areas; a nest less than 3 m from a doorway or an outdoor play area calls for intervention.
A nest more than 20 cm across indicates a well-established colony. Note the height, the orientation and the access routes to make professional intervention easier.
Prevention
- Inspect trees and eaves
Examine trees and structures in June and July to catch nests while they are still starting out (the size of an orange), before they reach their full size.
Trees - Reduce nesting sites
Prune dense hedges and bushy shrubs regularly, as they offer sheltered anchor points for founding queens.
Garden - Paint or treat exposed wood
The workers gather fibres from unpainted wood. Painting or varnishing wooden structures makes them less attractive as a source of building material.
Structure
Frequently asked questions
Is the bald-faced hornet dangerous?
Yes, near its nest: it defends it fiercely and can sting several times. At a distance it stays fairly unaggressive. The stings are painful and risky for people with allergies.
What does its nest look like?
A large grey paper nest, oval and closed, hanging in a tree, a shrub or under an eave; it can grow to the size of a balloon.
How do I recognize it?
A black body marked with white, larger than a common wasp (Dolichovespula maculata). It builds up high rather than in the ground.
How do I get rid of the nest?
Do not try to take it down. An exterminator treats the nest in the evening, once the workers are back inside, with the required protective equipment.