Depends on the location. Mosquito control is done all over, but I'm only somewhat familiar with north america.

It's pretty widespread in the United States where it's done by government employees at the municipal and county level I believe. They do use a fair bit of aerial spraying in certain areas though as I understand since there is a high concern of certain diseases being spread in certain areas.

In Canada it's mostly done by private companies (ironic I know) with a few areas being done by the government, and it's mostly done just because of nuisance and negative economic effects from outdoor workers and tourism so aerial spraying of chemicals is pretty much not done at all except for one major city which is phasing it out.

If you live anywhere in north America that's nearby a river, coast, swampland, or significant snowmelt into he spring, you may have a local mosquito control program.

I never even knew the control programs existed until I came across the job postings and got hired, but they are fairly wide spread.