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.
There should almost be some sort of technological transfer to nearby empires, like cultural influence. If your neighbour is at 10000 tech points or whatever while you are at 1000, you should be able to leech some tech points from your neighbour to develop faster.
Transfer rate increases with the disparity between nations and decreases with distance.
So a super advanced empire on continent A will contribute to nations on continent A and B, but those on continent A get more of a bonus than those on B.
This aligns fairly well with reality as neighbouring countries would transfer students to universities all the time, less so the further the nations are apart.