Does Your Area Have a Mosquito Control District?
Somewhere between 1,900 and 2,200 public bodies in the United States do some mosquito control, but only a minority are dedicated mosquito control districts, and the difference is large: in the most recent national assessment, 55 per cent of districts were rated fully capable against 2 per cent of local health departments. Whether your area has a district, and what it does, changes what a homeowner actually needs to buy. Districts treat public water, storm drains and wetlands; almost none of them treat your yard.
Most people do not know whether they live inside a mosquito control district. Some pay for one through their property taxes without realising it. Others assume the city sprays when nothing of the kind happens. Here is how the public system is organised, how good it is, and what it means for a private purchase.
How many programmes there are depends on who is counting
| Count | Who | Basis |
|---|---|---|
| About 734 organised mosquito control organisations | American Mosquito Control Association | No date or method published |
| 1,906 vector control organisations | NACCHO with CDC funding, 2017 | Every organisation identified by CDC, the association and NACCHO combined |
| 2,213 local vector programmes, 1,664 verified | NACCHO, 2020 assessment | Database count, contact confirmed for 1,664 |
The frequently repeated figure of 734 is the least useful of the three, because nothing on the page publishing it says how or when it was counted. The two NACCHO figures come from structured surveys. The defensible summary is that roughly 1,900 to 2,200 public bodies do mosquito work of some kind.
Most of them are not mosquito districts. In the 2017 survey, 20 per cent of responding programmes were mosquito control districts, 53 per cent were local health departments, and 27 per cent were other bodies, including public works departments, parish police juries and parks departments.
Who runs it matters more than anything else
NACCHO rated programmes against five core competencies: routine surveillance using standardised trapping and species identification, treatment decisions based on that surveillance, larviciding or adulticiding, routine control, and pesticide-resistance testing.
In 2020, 55 per cent of dedicated mosquito control districts met all five. Local health departments managed 2 per cent and city or county departments 3 per cent. Scale mattered too: programmes serving more than 500,000 people were 46 per cent fully capable, those serving under 50,000 were 3 per cent. NACCHO’s own recommendation, on the strength of its data, was to form mosquito control districts.
Most programmes were missing something basic
CDC’s 2018 summary of the 2017 survey put it bluntly: 84 per cent of local vector control organisations lacked at least one of the five core competencies. Among those, 98 per cent did no resistance testing, 61 per cent were not basing treatment on surveillance data, and 52 per cent did no routine surveillance at all. In 17 states, no responding programme met all five.
By 2020 the share rated fully capable had risen from 8 to 24 per cent, though NACCHO notes the two survey populations differ and the change was not tested for significance. Resistance testing remained the weak point, missing in 69 per cent of programmes.
Related: what California’s public health agencies actually apply is in California mosquito control pesticide data.
What a district does, and what it does not
One Illinois district’s annual report to the state gives a concrete picture of the work. Covering 242 square miles and about 800,000 residents on a $4.57 million budget, it ran light traps and gravid traps seven days a week, tested mosquito pools for West Nile virus, made 66,267 catch-basin larvicide treatments and 10,441 permanent-water treatments, adulticided 513 linear miles, and ran laboratory resistance testing. It employed 14 full-time and 40 part-time staff.
That is surveillance-led, area-wide work: storm drains, retention ponds, wetlands and public rights of way, triggered by trap counts and virus testing. What it is not is treatment of private yards. The containers, gutters, shrubs and shaded resting sites around a house are the homeowner’s responsibility almost everywhere.
One caveat belongs here: the measured advantage of districts is in how well they run surveillance and targeted treatment, not yet in proven differences in disease, and we found no study comparing health outcomes between areas with and without one. Whether spraying itself changes disease risk is covered in what mosquito spraying does about disease risk.
Where districts exist
| State | What exists |
|---|---|
| Florida | 66 state-approved districts as of 2021, the first founded in 1925, many with elected boards and property-tax funding |
| New Jersey | A mosquito control agency in all 21 counties, nine of them independent commissions, and a state aerial programme |
| California | Upward of 65 agencies, some also testing ticks and other vectors and stocking mosquitofish |
| Utah | 24 abatement districts in the state association directory |
| Louisiana | 16 districts, concentrated in the southern third of the state |
| Illinois | Abatement districts concentrated in the northeast, four in Cook County alone |
| Minnesota | One large metropolitan district covering seven counties |
Many other states have no district structure and leave mosquito work to county health departments, if anyone. North Carolina, for example, ended state mosquito funding to local governments in 2014.
What this means for what you buy
- Find out whether you are in a district. Your county or city website will usually say, and districts publish maps of their boundaries. If a line on your property tax bill mentions mosquito abatement, you already pay for one.
- If you are, you are buying yard comfort, not public health protection. The district handles the area-wide breeding and the disease surveillance. A private barrier treatment only addresses biting mosquitoes resting on your property.
- If you are not, source reduction around the house matters more, because nobody is treating the drains and ponds nearby.
- Report breeding sites. Districts respond to service requests for standing water on public land, abandoned pools and flooded lots, which is often the most effective call a homeowner can make.
Whether private spraying reduces disease risk is a separate question, covered in what mosquito spraying does about disease risk. What a residential programme costs is in mosquito control costs, and one-off treatment before an occasion in mosquito control for events. The storm-season side of mosquito pressure is in pests after a hurricane or flood.
Frequently asked questions
Does my city spray for mosquitoes?
It depends entirely on where you live. Some areas have a dedicated mosquito control district, some leave it to the county health department, and many have no routine programme at all. Check your county or city website or your property tax bill for a mosquito abatement line.
What is a mosquito control district?
A public body, usually a special taxing district or county agency, dedicated to mosquito surveillance and control across a defined area. In the 2020 national assessment, 55 per cent of districts met all five core competencies against 2 per cent of local health departments.
How many mosquito control programmes are there in the US?
Roughly 1,900 to 2,200 public bodies do some mosquito work, according to NACCHO counts from 2017 and 2020. Only a minority, around a fifth of survey respondents, are dedicated mosquito control districts; most are health departments or other local agencies.
Will the mosquito district treat my yard?
Almost never. Districts treat public water, storm drains, wetlands and rights of way, and respond to reports of breeding sites. Private yards, including containers, gutters and shrubs, remain the property owner’s responsibility.
Do mosquito districts reduce disease?
They are far better at surveillance and targeted treatment than other public programmes, but we found no study directly comparing disease outcomes between areas with and without a district.
Who do I call about mosquitoes breeding nearby?
Your local mosquito control district if you have one, otherwise the county health department. Standing water on public land, abandoned swimming pools and flooded lots are the kind of breeding sites they respond to.
Why do so many programmes lack basic capabilities?
Mostly funding and structure. Programmes run inside health departments or general city services rarely have dedicated staff, trapping or laboratory capacity. In 2017, 98 per cent of programmes needing improvement did no resistance testing and more than half did no routine surveillance.
Sources
- NACCHO and CDC, Mosquito Control Capabilities in the US, October 2017. stacks.cdc.gov
- NACCHO, 2020 Vector Control Assessment. naccho.org
- CDC Vital Signs, Illnesses from Mosquito, Tick and Flea Bites Increasing, May 2018. cdc.gov
- American Mosquito Control Association, Mosquito Control. mosquito.org
- Northwest Mosquito Abatement District, 2025 annual report to the Illinois Department of Public Health. nwmadil.gov
- McMillan JR et al., catch basin larviciding and West Nile virus, Pest Management Science, 2021. ncbi.nlm.nih.gov
- Kondapaneni R et al., Florida mosquito control districts, Pathogens 10(8), 2021. ncbi.nlm.nih.gov
- Rutgers Center for Vector Biology, New Jersey mosquito control organisations. rutgers.edu
