Field plate · Culex spp.
Mosquito
A summer-evening pest with a public-health file attached. Most Erie County mosquito trouble is a biting nuisance; some of it, in some summers, carries West Nile virus — and the county tests for exactly that.
Plate 23 of 28. Drawn in profile to the identification marks named below; the scale rule is a drawing convention — sizes are given in the text.
Identification marks
The mosquitoes that matter most around Erie houses are Culex species: small, brown, unremarkable flies that rest with the body parallel to the wall, bite from dusk into the night, and breed in still water — not in the lake. Females are the biters. What you can identify in practice is the setting: a dusk biter near a clogged gutter, a rain barrel, or a birdbath that has not been tipped in a week is a Culex problem until shown otherwise.
Look-alikes it is confused with
Crane flies (big, harmless, do not bite), midges off the lake (nuisance swarms, weak biters at most), and male mosquitoes (feathery antennae, do not bite). The dangerous confusion is the other way: assuming every dusk biter is harmless background noise in a summer when the county has announced positive samples.
Where it breeds around a house
Any water that stands for a week: clogged gutters and downspout elbows, tarps and tyre swings, flowerpot saucers, unchlorinated wading pools, open rain barrels, and the catch basins on the street. Culex does not need a pond — a bottle cap of stagnant water is a nursery, and a gutter is a housing development.
Health risk, stated plainly — West Nile in Erie County
West Nile virus is carried by Culex mosquitoes that have fed on infected birds. Most human infections cause no symptoms; about one in five brings fever and flu-like illness, and a small fraction — under one in a hundred — becomes serious neurological illness, with older adults at highest risk. This is not theoretical for Erie County: the Erie County Department of Health confirmed West Nile–positive mosquito samples collected in Millcreek Township, Harborcreek Township, and the City of Erie in July 2025 (eight positive samples that season), as part of its routine mosquito surveillance. A positive sample means the virus is circulating locally that summer — it is a reason for bite prevention, not panic. Seek care promptly for fever with severe headache, neck stiffness, confusion, or weakness after mosquito exposure, and tell the clinician about the exposure.
What actually works
Source reduction first, because it is permanent: tip, drain, or scrub anything that holds water, weekly; clean gutters; screen or mesh rain barrels. For water that cannot be drained, Bti dunks or bits (a biological larvicide, labeled for the use) kill larvae without spraying the yard. For people: an EPA-registered repellent used as labeled, long sleeves at dusk, intact window screens, and a fan on the porch — mosquitoes are weak fliers. County surveillance and larviciding of catch basins is the Erie County Department of Health's work; report standing-water problems and dead birds through the county's channels.
What doesn't
Bug zappers (they kill mostly harmless insects and do not meaningfully reduce biting Culex), ultrasonic devices, citronella candles beyond arm's length, and a one-off fogging presented as a season's protection. Barrier sprays can knock down resting mosquitoes for a short window but do nothing about the gutter breeding next door — and they are hard on pollinators when applied carelessly.
When to call a licensed pro
When the breeding source is off your property and beyond the county's response, when a large event needs a short treatment window, or when the yard is unusable despite honest source reduction. Ask what the treatment targets, how long it lasts, and what it does not do.