GM mosquito fights dengue by killing its own

This May Help Raise Tweaked Bugs To Fight Insect-Borne Diseases And Control Pests     These mosquitoes are genetically engineered to kill — their own children. Researchers on Sunday reported initial signs of success from the first release into the environment of mosquitoes engineered to pass a lethal gene to their offspring, killing them before they reach adulthood.      The results, and other work elsewhere, could herald an age in which genetically modified insects will be used to help control agricultural pests and insect-borne diseases like dengue fever and malaria. But the research is arousing concern about possible unintended effects on public health and environment, because once genetically modified insects are released, they cannot be recalled.      Authorities in the Florida Keys, which in 2009 experienced its first cases of dengue fever in decades, hope to conduct an open-air test of the modified mosquitoes as early as December, pending approval from the agriculture department.      "It's a more ecologically friendly way to control mosquitoes than spraying insecticides," said Coleen Fitzsimmons, a spokeswoman for the Florida Keys Mosquito Control District. The agriculture department, meanwhile, is looking at using genetic engineering to help control farm pests like the Mediterranean fruit fly, or medfly, and the cotton-munching pink bollworm, according to an environmental impact statement it published in 2008. Millions of genetically engineered bollworms have been released over cotton fields in Yuma County, Ariz. Yet even supporters of the research worry it could provoke a public reaction similar to the one that has limited the acceptance of genetically modified crops.      In particular, critics say that Oxitec, the British biotechnology company that developed the dengue-fighting mosquito, has rushed into field testing without sufficient review and public consultation, sometimes in countries with weak regulations.      "Even if harms don't materialize, this will undermine the credibility and legitimacy of the research enterprise," said Lawrence O Gostin, professor of international health law at Georgetown University. NYT NEWS SERVICE