Science News

Mosquito season approaches

Tuesday, March 9, 2010

Without a wing, there's not much of a prayer for female mosquitoes

First it was just swatting. Then poison. Then sterilizing males. Is there anything people won't try in the war against mosquitoes? The latest idea: Genetic engineering that results in flightless females.

Females do the biting, but if they can't fly they can't zoom in on their victims. They would be expected to die quickly on the ground, researchers suggest in a paper in a recent edition of the Proceedings of the National Academy of Sciences.

The real goal is to prevent mosquitoes from spreading disease, and the researchers, led by Luke Alphey of the University of Oxford, are studying ways to reduce the spread of dengue fever, found mostly in Asia, which mosquitoes carry.

The researchers, several of whom have commercial interests in the work, developed a method to genetically alter male mosquitoes, then release them to mate with females in the wild. The wing muscles of their female offspring would not develop properly, preventing them from flying. (Males don't inherit the defect.)

"It's far more targeted and environmentally friendly than approaches dependent upon the use of chemical spray insecticides, which leave toxic residue," Alphey said in a statement. Other efforts to block transmission of diseases such as malaria have involved releasing sterile male mosquitoes, which could breed with females but produce no offspring. Bed nets also are widely used, but the researchers said the dengue-spreading mosquitoes bite in daytime rather than at night.

Although this research is aimed at dengue, Alphey and co-author Anthony A. James of the University of California at Irvine said it could also be adapted to such diseases as malaria and West Nile fever.

-- Associated Press

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