Hornet

Which hornets live in Quebec?

Strictly speaking, "hornet" refers to the large wasps of the genus Vespa. In everyday Quebec usage the word covers more ground:

• The bald-faced hornet (Dolichovespula maculata) is by far the most common. Black with white markings on the face and the tip of the abdomen, it's 15 to 20 mm long. Technically it's a wasp, a close relative of yellowjackets, but bigger and more defensive.
• Other aerial wasps, such as Dolichovespula arenaria, yellow and black, also build hanging paper nests and often get called hornets.
• The European hornet (Vespa crabro), reddish-brown and yellow and 2 to 3.5 cm long, is rarely seen in Quebec. It nests in cavities (hollow trees, walls, attics) and may fly at night, drawn to lights.
• The Asian hornet and the northern giant hornet are not established in Quebec, whatever you may read on social media.

To tell a hornet, a wasp and a bee apart at a glance, see our guide wasp vs bee vs hornet: how to tell the difference.

Recognising a hornet nest

A bald-faced hornet nest is a grey paper ball or football made of chewed wood fibre, with a single opening near the bottom. It hangs from a branch, under eaves, a cornice, a soffit, a balcony or a shed — and sometimes low in a hedge or shrub, where nobody notices it until the hedge trimmer hits it.

The nest grows with the colony. In May and June the queen builds a golf-ball-sized nest on her own. Workers then take over and by August or September the nest can reach the size of a basketball or even exceed 50 cm. A hole in the siding, the ground or a wall with insects flying in and out is more likely a yellowjacket nest in a cavity: never plug it, as the wasps will look for another way out — sometimes into the house.

The real risks

Hornets aren't aggressive away from the nest, but they defend it hard. A vibration (lawn mower, ladder, hedge trimmer), a knock on the branch or an approach within a few metres can set off an attack by several of them at once. Their smooth stinger lets them sting again and again.

Most stings cause sharp pain, redness and local swelling that clears up within a few days. In people with an allergy, a sting can trigger a severe reaction. Call 911 right away if there is widespread hives, swelling of the face or throat, difficulty breathing or dizziness, and use an epinephrine auto-injector if one has been prescribed. For other health questions, Info-Santé is available by dialling 811.

What to do if you find a nest

• Keep children and pets away and avoid creating vibrations near the nest.
• Don't spray the nest yourself, hit it or try to pull it down — that's the most common way people end up with multiple stings.
• If the nest is high in a tree, well away from where people walk, it can often be left alone: the colony dies with the first hard frosts and the empty nest is never reused.
• If it's near a door, balcony, play area or window, have it removed by an equipped professional.

Our article on how to deal with a wasp nest covers the methods and the mistakes to avoid.

Preventing nests

Check eaves, soffits, sheds and balconies in late spring: a golf-ball-sized nest is far easier to deal with than a mature one in August. Seal gaps in soffits and siding, put fine screening over vents, keep garbage and compost bins tightly closed, pick up fallen fruit and cover sugary drinks outdoors in late summer.