Self-Destructing Mosquitoes Are Annihilating Wild Populations

Self-destructing mosquitoes are maybe possibly my favorite invention of the century. Okay, smartphones and Spotify are pretty great, too, but having just spent a couple of weeks in bug-infested New England, I might be a taaaad biased.

Mosquitos, as we know, are one of the main vectors of infectious disease worldwide, particularly in the tropics. Every year, the little bastards are responsible for 50 to 100 million cases of dengue fever and hundreds of millions of cases of malaria, not to mention yellow fever, chikungunya, and many, many more illnesses. Some mosquitoes are worse than others: the leading culprit behind many tropical diseases, for instance, is Aedes aegypti, a critter that thrives in urban areas and is highly resistant to insecticide.

In an experiment that might be construed as evil if we weren’t talking about mosquitoes, the insect control company Oxitec decided to see what happens when Aedes aegypti eggs are injected with a custom gene that hinders development. The gene doesn’t kill the mosquitoes outright, it simply prevents their offspring from reaching sexual maturity.

Once its genetically modified self-destruction bugs had reached adulthood, Oxitec began field trials, releasing them into the wild in dengue-ridden regions of Panama, Brazil, Malaysia, and the Cayman Islands. By unleashing ‘a sufficient number of male mosquitoes’ to outcompete the local bugs (this sounds like a horrifying experiment, if well intentioned), the company was able to suppress wild populations by over 90 percent. Oxitec is planning additional trials for the Florida Keys later this year, pending FDA approval.

The idea of releasing genetically modified mosquitoes to suppress wild populations isn’t new—in fact, the World Health Organization has been promoting the strategy for years—but the recent effort represents one of the largest and most successful field trials to date. Still it’s not entirely clear that genetically-modified bugs will become a long-term solution: Genes that have a negative effect on a population tend to get weeded out, quickly, by natural selection. And viruses have a nasty way of jumping from one host to another. It’ll take several years of field data to be able to say with any confidence that we’ve made a lasting dent.

Still, eliminating 9 out of 10 wild mosquitoes—without insecticide—is no small feat, and I for one am very interested to see how this effort develops.

[Popular Science]

Contact the author at maddie.stone@gizmodo.com or follow her on Twitter.

Top image via Shutterstock

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RussTShackelfordMaddie Stone
7/11/15 12:16pm

I don’t believe I’m the only one that is concerned about the loss of the essential biomass that is the ravenous horde we call Mosquitos.

Is this going to be another Harmonia axyridis fiasco?

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zimway2kMaddie Stone
7/11/15 12:26pm

Every year, the little bastards are responsible for 400 million cases of dengue fever and 300 to 600 million cases of malaria,

can this be true? in just 10-15 years, effectively the equivalent of the whole earth’s population can be infected? is it possible to get these diseases over and over...?

3 Reply
- Maddie Stonezimway2k
  7/11/15 12:58pm
  
  The 400 million figure was pulled from Popular Science. I’ve done a little more digging and that’s actually on the high side —the World Health Organization estimates 50-100 million cases a year, so I’ve revised the number down. That’s still a lot of cases, but yes, you can contract dengue multiple times. It’s sorta like a very bad case of the flu.
  
  1 1 Reply
- zimway2kMaddie Stone
  7/11/15 1:20pm
  
  yah, I think the source content was questionable mostly in its ambiguity of statement. likely, it’s meant to say that 400-600 million people suffer worldwide. so every year there are 400-600 million people suffering. but 50-100 million new cases are added each year? or just 50-100 million total sufferers? ahhh, the english language.... :)
  
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