In an effort to create new tools to control the population of disease-carrying pests (or just pests in general), researchers in the U.K. have modified certain mosquitoes with a lethal gene that kills offspring before they mature and bite people. This isn't just something happening in a lab, either — they've already been released.
The mosquito in question is the Aedes aegypti, or the "yellow fever mosquito." The Aedes aegypti female's bite can carry the likes of yellow fever, dengue fever and other diseases, and make it a deadly pest all over the world, but especially in developing countries. It's worth noting here that male mosquitoes usually stick to plant nectar and so on, whereas the ectoparasitic lady 'squitoes go after a "blood meal" to produce eggs or increase egg production. It's the males that are being released into wild families of Aedes aegypti. Releasing females would introduce a whole host of new variables as they interact with other animals and people while sucking blood.
The gene-modded Aedes aegypti are grown in a lab. The deadly gene they're tailored to have will kill them if they are not vaccinated within the lab's confines — which means, once released, they only have a short period of time to mate before they die, too.
Into The Wild
On Sunday, a study was released analyzing the effectiveness of using modified mosquitoes on Aedes aegypti populations on Grand Cayman island in the Florida Keys back in 2009. 19,000 mosquitoes with the killer gene were used, according to the New York Times:
Based on data from traps, the genetically engineered males accounted for 16 percent of the overall male population in the test zone, and the lethal gene was found in almost 10 percent of larvae. Those figures suggest the genetically engineered males were about half as successful in mating as wild ones, a rate sufficient to suppress the population.
2009 was the first release of the mosquitoes into regular Aedes aegypti families. A larger trial in 2010 is said to have reduce the Aedes aegypti population on Grand Cayman by "80 percent for three months," though that hasn't been confirmed.
Modifying an insect so that its very genes are lethal to its own kind may sound like a brutal form of population control, but supporters of the plan point out that it has less of an ecological impact than, say, damaging and powerful pesticides. The worry, of course, is that these genetically modified mosquitoes will, in turn, produce a modified disease, one that could be even worse than what they've been bred to combat.
Genetically modified anything is obviously fighting an uphill battle to begin with. Whether or not this will be a victory for the procedure or — as it is with genetically modified food — something that turns people off to the idea remains to be seen.