In many parts of the eastern United States, getting rid of mosquitoes has become just another household service. Homeowners hire private companies to spray their yards, or they buy insecticides and foggers themselves, hoping to reclaim summer evenings from constant bites.

The choices people make to control mosquitoes in their own backyards may be helping some of those mosquitoes survive the very insecticides meant to kill them, according to two new…

In many parts of the eastern United States, getting rid of mosquitoes has become just another household service. Homeowners hire private companies to spray their yards, or they…