The EPA Just Approved Lab-Grown Mosquitoes to Fight Disease

Image: Getty
Image: Getty

Killer mosquitoes are coming—mosquitoes that help kill other mosquitoes, that is.

The Environmental Protection Agency has approved lab-reared mosquitoes infected with the bacterium Wolbachia pipientis to be released into the wilds of 20 states and Washington, DC. The mosquitoes are engineered by the company MosquitoMate so that they deliver the bacterium to wild mosquitoes when released, killing off insects that could transmit viruses such as dengue, yellow fever and Zika.

The technique is a riff on an approach used to manage agricultural pests for more than half a century known as “sterile insect technique.” Using radiation to randomly cause an insect’s genes to mutate, scientists made problematic species like the screwworm unable to produce viable offspring. By 1982, screwworm was completely eradicated from the US.


Mosquitoes, though, are too fragile to blast with rays of radiation and still be capable of mating in the wild, forcing scientists to turn to other techniques such as genetic engineering or, in this case, the Wolbachia bacterium. The company will rear the infected mosquitoes in its Kentucky lab, sorting non-biting males from females. Then those males will be released at treatment sites to mate with wild females, producing eggs that don’t hatch because the virus prevents paternal chromosomes from developing properly. The idea is that over time, as more male mosquitoes are released to mate with wild females, the population dwindles—without having to resort to pesticides that are not only harmful to people and the environment, but rapidly dwindling in efficacy.

The news was reported first on Tuesday in Nature, and confirmed to Gizmodo by MosquitoMate and the EPA. The EPA said that on November 3 the agency officially registered MosquitoMate’s Asian Tiger mosquito as a new biopesticide, with a five-year license to sell in 20 different states.

MosquitoMate CEO Stephen Dobson told Gizmodo that the company will begin releasing the mosquitoes in the Lexington area next summer, and gradually expand to other nearby metropolitan areas like Nashville and Louisville. The company will contract with local government bodies, as well as sell the mosquitoes direct to home owners via a summer-long subscription.

MosquitoMate is not the only entity to explore the use of lab-grown mosquitoes to kill off pests, but its approach has been far less controversial than some others because it is perceived as a “natural” alternative to pesticides. The British biotech company Oxitec has for years sought approval to release genetically engineered sterile insects in the US, but so far has yet to even gain approval for open-air tests. In the Florida Keys, for example, the local community railed against Oxitec’s mosquitoes, forcing the company to seek a new location for its trials after a local vote. Meanwhile, MosquitoMate’s trials in the Keys and Fresno, CA attracted little attention.


Dobson told Gizmodo that it is also pursuing the release of the Asian Tiger mosquito nationwide, as well as trials of another species of mosquito, the Aedes aegypti—one of the deadliest species of mosquitoes.

Senior Writer, Gizmodo.

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Still Cat from MA

The company I have heard most often for the technology of producing sterile male mosquitoes to reduce disease-carrying popolations is the British-based Oxitec. They have been working on this technology for years, with proven success in trials in several tropical areas and are now beginning to work to reduce mosquitos carrying Dengue, Zika and chikungunya viruses in Brazil:

For years Oxitec has tried to get approval of their approach to fight malaria and viruses in the Southern US, pointing to dramatically positive results of trials in other countries:

Last time I heard (the second link above, written July 2016), the Florida Keys residents where they wanted to do a US trial basically said they preferred malaria to sterile GMO mosquitoes, no matter how safe it had already been shown to be. Which is really too bad for them, their children and the many vulnerable elderly people in that area:

Now, with a severe outbreak of Zika spreading across the world, the need for an efficient and effective mosquito solution has never more urgent. Still, Oxitec is months away from being able to use the groundbreaking technology on U.S. soil. It’s not the government that is keeping the Oxitec mosquitoes off the land—based on the FDA’s recommendation they could start tomorrow. It’s the people of southern Florida themselves who are boycotting—people who are unwilling to believe that anything modified by science is safe.

In defiance, residents of southern Florida have launched an opposition campaign that includes putting signs in their yard that read “No Consent.” One resident, Mila Demier, started a petition on requesting that Oxitec be banned from releasing the mosquitoes. “Don’t let Oxitec bully our community!” she writes. “We say no to genetically modified mosquitoes in the Florida Keys!” [...]

So I was wondering what is happening now wth the long struggle to get approval for Oxitec to start killing disease-carrying mosquitoes in the US (they also have a program for eliminating a moth pest). I checked their web site ( and found this:

Transfer of Regulatory Jurisdiction for Oxitec’s Self-limiting Friendly™ Aedes in the United States

OXFORD, UK, October, 4, 2017 – Following new Guidance issued by the U.S. Food and Drug Administration’s Center for Veterinary Medicine (FDA-CVM), regulatory jurisdiction for Oxitec’s Friendly™ Aedes mosquito (OX513A) will now move under the Environmental Protection Agency (EPA) as a pesticide product. Oxitec has been in consultation with EPA regarding the regulatory process and, given this clarification of the regulatory jurisdiction, intends to submit an application to EPA for registration of OX513A.

The FDA-CVM’s Final Guidance for Industry clarifies “that mosquito-related products intended to function as pesticides by preventing, destroying, repelling, or mitigating mosquitoes for population control purposes, and that are not intended to cure, mitigate, treat or prevent a disease (including by an intent to reduce the level, replication or transmissibility of a pathogen in mosquitoes), are not “drugs” under the Federal Food, Drug, & Cosmetic Act, and will be regulated by the EPA under the Federal Insecticide, Fungicide, and Rodenticide Act…With the issuance of final guidance #236, Oxitec Ltd’s genetically engineered mosquito, with its proposed claim to control the population of wild-type Aedes aegypti mosquitoes, now falls under EPA’s regulatory authority and all related regulatory questions should be directed to the EPA.

So Oxitec is only just now applying for EPA approval because the government changed the rules under which such approval can be given. Must be very frustrating for them. I wonder how MosquitoMate got such a head start over them in the EPA approval process.

Their technology is safe and proven, and the need is great. Pesticide-resistant mosquitoes are spreading, and pesticides carry their own dangers anyway. There are other approaches under development, like a fungus that targets mosquitoes (, but for now the Oxitec approach seems the most promising. (The MosquitoMate approach is conceptually similar but uses a bacterium instead of mutation. Would be interesting to know which would be safer and more effective in a head to head trial, but I would bet on the simpler Oxitec approach.)

(ETA: I have no affiliation with either company and a background in biochemistry and cell biology.)