Every year, mosquitoes infect 400 million people with dengue fever, causing severe headaches and joint pain. Since a 2009 outbreak in Key West, the Florida Keys Mosquito Control District has spent $1 million a year to try to curb the primary vector: Aedes aegypti. Last July, another mosquito-borne virus reached U.S. shores: chikungunya. Now officials are considering a radical—and highly controversial—approach to control the spread of tropical disease: genetically modified mosquitoes. http://www.popsci.com/mosquitoes-designed-self-destruct.