Identification
Dolichovespula maculata is misleadingly named. It is not a true hornet (the only true hornet in North America is the introduced European hornet, not established in BC, and the Asian giant hornet, which had isolated Nanaimo detections but has not established in Metro Vancouver). D. maculata is technically a yellowjacket in the genus Dolichovespula. Workers are 18 to 20mm long — noticeably larger than the common yellowjacket — with striking black-and-white colouration (not yellow) on the face and abdomen. The face is almost entirely ivory-white, which gives the species its name. Queens are 20 to 25mm. The diagnostic sign is the nest: a grey paper sphere the size of a football (sometimes larger), hanging from a tree branch 2 to 10 metres up, or attached to the side of a building high under an eave. The nest has a clear entry hole at the bottom and is fully enclosed in a paper envelope.
Habitat in BC
Bald-faced hornet nests hang in high, open locations across Metro Vancouver. Most are in mature deciduous trees — big-leaf maple, birch, alder, fruit trees — at 3 to 10 metres height. A smaller proportion attach to building exteriors, usually under eaves at the second-storey level or higher, occasionally on chimney faces or in roof-peak corners. They rarely nest in cavities or low shrubs. Geographic distribution is region-wide but particularly heavy in neighbourhoods with mature tree canopy: Kitsilano, Point Grey, Dunbar, South Granville, Shaughnessy, Oakridge, West Vancouver, North Vancouver, and the mature residential areas of Burnaby and New Westminster. Rural and wildland-edge properties see the heaviest pressure.
Signs you have bald-faced hornet
- A football-sized grey paper sphere hanging from a tree branch, eave, or building face — the single most diagnostic and impossible-to-miss sign.
- Large (18–20mm) black-and-white wasps patrolling a 5 to 10 metre radius around the nest.
- Steady traffic of hornets entering and exiting a single point at the base of the sphere.
- Aggressive investigation of anyone approaching within 3 metres of the nest — bald-faced hornets are known for zone-defence behaviour.
- Chewed wood fibre harvesting visible on weathered fences, old decks, or unpainted outbuildings nearby.
Risk & damage
Bald-faced hornets are arguably the most defensively aggressive social wasp in BC. They will aggressively pursue perceived threats 5 to 10 metres from the nest, and unlike honeybees they can sting repeatedly. Their sting is documented as among the most painful of North American Hymenoptera on the Schmidt Sting Pain Index. Because nests are frequently 3 to 10 metres up in trees, DIY attempts to knock them down from the ground with a ladder and aerosol spray produce some of the most severe multi-sting incidents we see in Metro Vancouver — dozens of stings in seconds, falls from ladders, and hospitalisation are all documented outcomes. For allergic individuals, a disturbed bald-faced hornet nest is an immediate life-threatening situation. Treat this species with maximum caution.
Seasonality in Metro Vancouver
Bald-faced hornet season follows the social-wasp arc: queens emerge in April, initiate small starter nests by May, colonies grow through summer, peak in August and September with 400 to 700 workers (smaller than yellowjacket peak but still substantial), and decline through October. First frost ends the colony. A completed D. maculata nest may be 30 to 50cm in diameter at peak. The old nest persists through winter as a weathered paper shell but is never reused — next year's queens always build fresh. Metro Vancouver's coastal climate extends the active season slightly longer than interior BC, with Vancouver-proper nests sometimes active into late October.
Treatment approach
Bald-faced hornet treatment is a specialised wasp call because of nest height, colony aggressiveness, and the confined-approach risk. Standard protocol is dusk or dawn treatment when most foragers are inside the nest, using an extended-reach applicator to deliver a registered pyrethroid dust directly into the entry hole while the technician wears full bee-suit PPE. The colony collapses within 24 to 48 hours. Physical nest removal is done the following day after confirming zero flight activity. For very high nests (above 8 metres), we use articulating lifts or rope-access techniques. Because of the height, PPE, and time involved, bald-faced hornet treatment runs at premium pricing — typically $275 to $450 depending on height and access. Never our $195 base rate.
When to call a professional
Always call. Bald-faced hornets are the single wasp species where we most strongly discourage any DIY attempt. The combination of height, colony size, and aggressive zone-defence behaviour means that consumer aerosol sprays and ladder-from-below approaches produce predictable serious injuries. We have treated more than a few homeowners post-incident — multiple stings, ladder falls, hospital visits — who attempted DIY on a nest they should have called for. Same-day response is available during peak season (July through September).
Prevention playbook
How to prevent bald-faced hornet in Metro Vancouver homes
- 1
Spot early-season nests in trees and shrubs
In May-June bald-faced hornet nests are baseball-sized and relatively safe to treat. Walk property perimeter and note any small paper spheres in shrubs, trees, or under overhangs.
- 2
Prune dense shrubs away from building exteriors
Bald-faced hornets favour enclosed branches and low tree limbs for nest sites. Prune vegetation 1m+ from building walls and eliminate dense shrub cover near entrances.
- 3
Never disturb an active nest
Dolichovespula maculata is the most aggressive stinging insect in BC. They sting repeatedly, spray venom, and defend nests from 3-5m away. DIY attempts on active nests regularly end in ER visits.
- 4
Schedule nest removal for any within 10m of a home
Even small early-season nests near entryways, children play areas, or outdoor living spaces warrant professional removal. The economics of prevention vastly beat the cost of a sting-incident lawsuit for strata or rental property managers.
- 5
Leave old fall nests alone
By mid-October BC colonies collapse and nests are abandoned. Winter nest removal (Dec-Feb) is safe and optional — they do not reoccupy old nests next year.
The Wild Pest service
See our Bald-Faced Hornet treatment page
Transparent pricing, 60-day return guarantee, same-day response across Metro Vancouver. Every treatment is documented with photos and service notes.
Frequently asked questions about bald-faced hornet
Are bald-faced hornets actually hornets?+
No, taxonomically. Dolichovespula maculata is a yellowjacket in the genus Dolichovespula, despite the common name. True hornets belong to the genus Vespa; the only true hornet native to North America is none — all North American 'hornets' are introduced or misnamed. In Metro Vancouver, the two hornet names you may hear are 'bald-faced hornet' (D. maculata, widespread) and 'Asian giant hornet' (Vespa mandarinia, detected in Nanaimo in recent years but not established in Metro Vancouver).
How aggressive are they really?+
Very. Bald-faced hornets practice zone defence — workers patrol 5 to 10 metres from the nest and will actively pursue intruders, including chasing humans 20 to 30 metres from the initial encounter. They can sting repeatedly. Their venom is ranked among the more painful of North American stings. Disturbing a D. maculata nest is one of the highest-risk wildlife encounters most BC homeowners will ever face — substantially more dangerous than most bear, cougar, or coyote encounters in a given summer.
What if the nest is 8 metres up in a tree — can you even reach it?+
Yes. We use extended-reach pole applicators to 6 metres, articulating lifts for 6 to 12 metres, and rope-access techniques for nests beyond that. No reasonable bald-faced hornet nest is out of reach — but access complexity drives price. A standard tree-branch nest at 5 to 7 metres typically runs $275 to $375; lift-required nests run $375 to $600; rope-access situations are quoted case-by-case.
Can I wait until winter and just knock the empty nest down?+
For a nest that poses no current risk to you (isolated backyard tree, no daily traffic), waiting for first frost is a legitimate option. By November the colony is dead, the nest is empty, and removal is harmless. If the nest is near a deck, entrance, playground, or walking path, waiting is not reasonable — sting risk escalates through August and September as the colony peaks. Call for immediate treatment in any high-traffic scenario.
Will they come back to the same tree next year?+
Not the same colony — every colony dies with first frost. But the tree or eave is often re-used by a new queen the following spring because the microclimate suits D. maculata. Homes with annual bald-faced hornet pressure benefit from spring preventive treatment (April or early May) at common harbourage surfaces, which is part of our quarterly plan. Removing the old winter nest does not prevent re-colonisation.
What about Asian giant hornets?+
Vespa mandarinia had confirmed detections in Nanaimo (Vancouver Island) in 2019 and subsequent years but has not established a reproducing population in Metro Vancouver as of 2026. BC Ministry of Agriculture and provincial invasive-species partners maintain active surveillance. If you believe you have seen a Vespa mandarinia specimen — notably larger than any D. maculata, 35 to 50mm with distinctive orange-yellow head — report to the BC Invasive Species Council immediately. Regular bald-faced hornet identification is almost always the actual finding.
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