Mosquitoes are developing resistance to the potions we use to kill them, reports The Washington Post. In a study in Cambodia and Vietnam, 78 percent of mosquitoes sampled by researchers had a genetic mutation that made them resistant to permethrin, a common insecticide. This mutation has been seen previously, but never in such high proportions. In the Cambodian capital, Phnom Penh, one insecticide used killed only 10 percent of mosquitoes, and another didn’t get rid of any. The researchers say the mutation is confined to Southeast Asia for now, but that the mosquito in question—Aedes aegypti, which carries dengue, yellow fever, chikungunya, Zika, and other diseases—is a hardy traveler. “They like artificial water containers, including jars, used tires, plastic cups, basins, and pods,” says lead author Shinji Kasai, from…