In South Florida, "mosquitoes" is the catch-all word for any flying biting insect. But the tiny invisible things biting you at dusk on the patio might not be mosquitoes at all — they might be no-see-ums (biting midges, Culicoides species), which are a completely different type of insect with different biology, different peak times, and different breeding sources.
Understanding which pest you're dealing with changes what you do about it.
No-See-Ums vs Mosquitoes: Side-by-Side Comparison
| Factor | No-See-Ums (Biting Midges) | Mosquitoes |
|---|---|---|
| Size | 1–3mm — barely visible to naked eye | 4–10mm — clearly visible |
| Visibility | Invisible in flight — hence 'no-see-ums' | Visible when near you |
| Scientific name | Culicoides species | Aedes, Culex, Psorophora, others |
| Peak activity time | Strict dusk/dawn windows (30–60 min each) | Dusk/dawn (Culex); daytime shade (Aedes) |
| Bite character | Multiple tiny dots, intense itch, longer duration | Individual raised welts, moderate itch |
| Breeding source | Moist coastal soil, salt marsh, mangroves | Standing freshwater — containers to lakes |
| Flight range | Very short (usually <100m from breeding site) | 1/4 mile to 3 miles depending on species |
| Wind sensitivity | Deterred by breeze >3–4 mph | Active in light wind |
| Disease risk (US) | None known in humans in South Florida | West Nile, dengue, chikungunya, Zika |
| Passes through 16-mesh screen | Yes — too small to be stopped | No — stopped by standard screening |
| Professional spray effective? | Yes — same pyrethroids work on both | Yes |
Where No-See-Um Pressure Is Worst in South Florida
No-see-ums are primarily a coastal pest — populations are concentrated near their breeding habitat (salt marsh, mangrove edges, tidal pools) and decline rapidly with distance inland. Properties with the highest no-see-um pressure in Boca Raton and Fort Lauderdale:
Adjacent to tidal vegetation breeding areas; zero buffer between breeding habitat and outdoor living
Tidal influence in Fort Lauderdale canals creates brackish breeding conditions for midges
Spanish River Park, Hugh Taylor Birch, Markham Park have significant midge breeding in adjacent natural areas
Mangrove vegetation is one of the primary Culicoides breeding habitats in South Florida
What Actually Works for Each
For No-See-Ums
For Mosquitoes
Ready to reclaim your yard? Free assessment — no contracts, plant-oil formula.
Frequently Asked Questions
How do I know if I'm being bitten by no-see-ums or mosquitoes?
The easiest way to tell: (1) If you can't see what's biting you despite looking carefully, it's almost certainly no-see-ums (biting midges). They are 1–3mm — barely visible to the naked eye. (2) No-see-um bites often appear as clusters of tiny red dots in exposed areas (ankles, wrists, neck), while mosquito bites tend to be individual raised welts. (3) No-see-um bites typically itch more intensely and longer than mosquito bites — the midge's saliva causes a stronger delayed immune reaction in most people. (4) Timing: if biting is worst exactly at sunrise/sunset within 50 meters of the water or coastal edge, no-see-ums are highly likely. If biting is worst at dusk in your lawn or garden, mosquitoes are more likely.
Are no-see-ums more dangerous than mosquitoes?
For disease transmission in the U.S. context, no — no-see-ums (Culicoides biting midges) are not known to transmit human diseases in the United States. In tropical regions, Culicoides can transmit bluetongue (livestock), but in South Florida they are a nuisance pest rather than a disease vector. Mosquitoes — particularly Aedes and Culex species — are the primary disease vectors in our region (West Nile, dengue, chikungunya, Zika). In terms of bite discomfort, many people find no-see-um bites worse than mosquito bites due to the more intense and prolonged itching reaction.
Can mosquito spray kill no-see-ums?
Yes — professional pyrethroid barrier spray (bifenthrin, permethrin) kills no-see-ums on contact and provides residual control against them. No-see-ums are not flying pests in the traditional sense — they are weak fliers that rest in coastal vegetation and are susceptible to the same barrier spray treatment used for mosquitoes. However, no-see-ums can enter through standard window screening (they're small enough to fit through 16-mesh screen), and their coastal breeding habitats (salt marshes, mangrove areas) cannot be treated by individual homeowners. Our barrier spray program significantly reduces no-see-um activity on treated properties.
When are no-see-ums worst in South Florida?
No-see-ums in South Florida are most active in two windows: (1) Dusk and dawn — particularly in the 30–60 minutes immediately before and after sunrise/sunset. This is a tighter and more predictable window than mosquitoes. (2) On calm, humid days near coastal areas — any reduction in wind speed allows no-see-um populations to become active. They are significantly deterred by even a light breeze (above 3–4 mph), which is why a ceiling fan can meaningfully reduce no-see-um biting on a screen porch while having little effect on mosquitoes.
Do no-see-ums breed in standing water like mosquitoes?
No — this is a key difference. No-see-ums breed in moist soil and organic debris in coastal environments — salt marsh edges, mangrove areas, moist sandy soil with decaying vegetation, and tidal pools. They do not breed in standing freshwater containers or ponds like mosquitoes do. This means that the standing water elimination advice that applies to mosquito control has no impact on no-see-um populations. No-see-um populations are driven by their coastal habitat conditions, not by homeowner-manageable water sources.
Does window screening keep out no-see-ums?
Standard 16-mesh window and door screening does NOT keep out no-see-ums — they are small enough to pass through. No-see-um screening is available with finer mesh (32-mesh or 'no-see-um screen') that does exclude them. The trade-off is reduced airflow. For screen rooms and enclosures in areas with significant no-see-um pressure, 32-mesh no-see-um screen provides meaningful protection. For most homeowners, barrier spray treatment of exterior vegetation combined with ceiling fans or light air movement provides better practical no-see-um management than trying to screen them out.
Our Service Controls Both Mosquitoes and No-See-Ums
Professional barrier spray with Rain Shield formula. FL License JB313837. Free property assessment — no commitment.
After nearly two decades in corporate finance — including managing a $1B+ P&L at Chico's FAS — Eric Vincent earned his MBA from Rollins College and made a deliberate pivot into pest control, completing his Pest Control Technology degree at the University of Florida while building Mosquito Shield of Boca and Fort Lauderdale from the ground up. He holds five Florida state licenses including Certified Pest Control Operator (JF341961) and Public Health licensee (PH340549), and is currently partnered with Arkion Life Sciences on next-generation all-natural mosquito control research.