And, New Scientist points out, they’re here to help… because they breed fast and their young die too quickly to spread dengue fever:
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.
The GM mosquitoes were designed by Oxitec of Abingdon, UK, and are bred en masse in a factory in Campinas, Brazil. The firm has a permit to commercialise and release the mozzies anywhere in Brazil.
Oxitec is also waiting for a permission from the US Food and Drug Administration (FDA) to test the mosquitoes on Key Haven in the Florida Keys.
Since April, 6 million GM mozzies have been released in the suburb of Piracicaba that is worst infested by Aedes aegypti, a mosquito that spreads the dengue fever virus.
“They’ve asked us to take on the neighbourhood that’s the worst to prove it works,” says Hadyn Parry, chief executive of Oxitec. “We hope that if it does, we can expand to a larger number of areas.”
The GM mosquitoes also carry a gene that makes the larvae they sire glow red under ultraviolet light, which allows scientists to see by eye how well the strategy is working.
By leaving pots of water, in which female mosquitoes lay eggs, at strategically important sites in the treatment zone, researchers can tell by counting the proportion of red larvae how well the treatment is working.
So far, the pot-survey has revealed that half of the larvae in the area have been sired by the GM mosquitoes.
Of course this has “unintended consequences” written all over it. I just wonder what they’ll be….
And of course, Florida’s next. Of course.