http://www.newscientist.com/article/dn27844-modified-mosquitoes-begin-blitz-on-dengue-in-brazilian-city.html?utm_source=NSNS&utm_medium=SOC&utm_campaign=hoot&cmpid=SOC%7CNSNS%7C2015-GLOBAL-hoot#.VZsPvbmqpBc The insect assassins have been launched. Millions of genetically modified mosquitoes have descended on the Brazilian city of Piracicaba in the battle against dengue and a test in Florida is also in prospect. The GM mosquitoes are all male, and when they mate with native females, they pass on a gene to offspring that causes the larvae to die before they mature. via Modified mosquitoes begin blitz on dengue in Brazilian city - health - 06 July 2015 - New Scientist.