One of the techniques used to eradicate malaria in the past was to spray the interior walls of houses with DDT. After feeding on human hosts who were infected with malaria, the mosquitoes would land on a nearby wall to digest the blood. If the wall was covered with DDT, then it would kill the mosquito before it had a chance to bite another person.[1]

[1] https://www.newyorker.com/magazine/2001/07/02/the-mosquito-k... (I think, the article is paywalled.)