We may receive a commission on purchases made from links. If you're someone who is frequently the target of mosquito bites, you've likely started to associate the sound of roving pesticide trucks with a feeling of relief. Some mosquito populations are developing resistance to pyrethroid-based insecticides, and data show that the problem is spreading. With mosquito season starting earlier and earlier, this trend should matter to homeowners, both for their comfort and health. Mosquitoes are annoying regardless, but they're also capable of spreading diseases like West Nile virus and dengue in the United States.