Mosquitoes! Am I right? Nasty pests that serve no useful function as far as I can tell. And they’re infamous for spreading a variety of deadly diseases. In fact, depending on how you measure it, mosquitoes kill more people each year than any other animal, adding up to more than a million deaths annually. But now there’s a new type of mosquito hanging out in the Florida Keys. It’s one that’s never been seen before because scientists genetically modified the species in an effort to use them in a genocidal war against their own kin. Thus far, the scientists seem to be declaring the experiment a success. But that sort of ignores the fact that there are now five million genetically modified super-mosquitoes roaming around Florida. (Nature Journal)

Researchers have completed the first open-air study of genetically engineered mosquitoes in the United States. The results, according to the biotechnology firm running the experiment, are positive. But larger tests are still needed to determine whether the insects can achieve the ultimate goal of suppressing a wild population of potentially virus-carrying mosquitoes.

The experiment has been underway since April 2021 in the Florida Keys, a chain of tropical islands near the southern tip of Florida. Oxitec, which developed the insects, released nearly five million engineered Aedes aegypti mosquitoes over the course of seven months, and has now almost completed monitoring the release sites.

Based in Abingdon, UK, the firm reported the first results from the experiment during a webinar on 6 April, although it has not yet published the data.

Okay, so let’s see how this is supposed to work, shall we? This British company, Oxitec, genetically engineered some of the A. aegypti mosquito (also known as the Yellow Fever Mosquito) so that the males inherited a particular new gene. When the males fertilize the eggs of females, the offspring inherit the gene. The gene has no effect on the male offspring but it causes a destructive mutation in all of the female offspring, leading them to die before they can reproduce. In theory, they would begin drastically reducing the population of female mosquitoes until there were so few mating options for the males that the population should shrink drastically.

Oxitec bred 5 million of these modified males and released them at test sites around one of the Florida Keys. They set up traps and feeding stations in the surrounding area to monitor the population over the next year. They recovered tens of thousands of eggs, taking them back to the lab to monitor their progress. They also monitored the adult population to see how far they spread from the initial breeding sites. Sure enough. the female babies almost all died before becoming old enough to breed.

But how could they tell which mosquitoes and eggs had the modified gene? Easy. Another modification makes them glow in the dark when you hit them with a blacklight. So yes… you heard that correctly. They released five million genetically modified, glow-in-the-dark Yellow Fever Mosquitoes into the Florida Keys.

In all seriousness, this sounds kind of promising. These mosquitoes are known to carry not only yellow fever virus, but also chikungunya, dengue, and Zika. If there really is a way to wipe them out, that would be a significant benefit. But I can’t escape the nagging fear that any of these genetic modification experiments instills in me. If you can mutate the mosquitos in your laboratory, what’s to stop them from mutating even further in the wild? Oxitec claims that the mutated gene disappears in the males after three generations. But what if the gene changes further? It always just seems like we’re playing with fire when we mess around with this stuff. But it’s too late to worry about it now, I guess. There are already millions of them buzzing around in Florida. And who knows if any of them have already caught a lift on a charter boat back to the mainland?