Genetically modified mosquitoes could be released in Florida and Texas beginning this summer – silver bullet or jumping the gun?

In 2018 scientists of the Miami-Dade County Mosquito Control tested a new way to suppress mosquito populations carrying the Zika virus. RHONA WISE/AFP via Getty Images

Brian Allan, University of Illinois at Urbana-Champaign; Chris Stone, University of Illinois at Urbana-Champaign; Holly Tuten, University of Illinois at Urbana-Champaign; Jennifer Kuzma, North Carolina State University, and Natalie Kofler, University of Illinois at Urbana-Champaign

This summer, for the first time, genetically modified mosquitoes could be released in the U.S.

On May 1, 2020, the company Oxitec received an experimental use permit from the U.S. Environmental Protection Agency to release millions of GM mosquitoes (labeled by Oxitec as OX5034) every week over the next two years in Florida and Texas. Females of this mosquito species, Aedes aegypti, transmit dengue, chikungunya, yellow fever and Zika viruses. When these lab-bred GM males are released and mate with wild females, their female offspring die. Continual, large-scale releases of these OX5034 GM males should eventually cause the temporary collapse of a wild population.

However, as vector biologists, geneticists, policy experts and bioethicists, we are concerned that current government oversight and scientific evaluation of GM mosquitoes do not ensure their responsible deployment.

Genetic engineering for disease control

Coral reefs that can withstand rising sea temperatures, American chestnut trees that can survive blight and mosquitoes that can’t spread disease are examples of how genetic engineering may transform the natural world.

Genetic engineering offers an unprecedented opportunity for humans to reshape the fundamental structure of the biological world. Yet, as new advances in genetic decoding and gene editing emerge with speed and enthusiasm, the ecological systems they could alter remain enormously complex and understudied.

Recently, no group of organisms has received more attention for genetic modification than mosquitoes – to yield inviable offspring or make them unsuitable for disease transmission. These strategies hold considerable potential benefits for the hundreds of millions of people impacted by mosquito-borne diseases each year.

Although the EPA approved the permit for Oxitec, state approval is still required. A previously planned release in the Florida Keys of an earlier version of Oxitec’s GM mosquito (OX513) was withdrawn in 2018 after a referendum in 2016 indicated significant opposition from local residents. Oxitec has field-trialed their GM mosquitoes in Brazil, the Cayman Islands, Malaysia and Panama.

The public forum on Oxitec’s recent permit application garnered 31,174 comments opposing release and 56 in support. The EPA considered these during their review process.

In 2016, technicians from the Oxitec laboratory located in Campinas, Brazil, released genetically modified mosquitoes Aedes egypti to combat the Zika virus. Victor Moriyama / Getty Images

Time to reassess risk assessment?

However, it is difficult to assess how EPA regulators weighed and considered public comments and how much of the evidence used in final risk determinations was provided solely by the technology developers.

The closed nature of this risk assessment process is concerning to us.

There is a potential bias and conflict of interest when experimental trials and assessments of ecological risk lack political accountability and are performed by, or in close collaboration with, the technology developers.

This scenario becomes more troubling with a for-profit technology company when cost- and risk-benefit analyses comparing GM mosquitoes to other approaches aren’t being conducted.

Another concern is that risk assessments tend to focus on only a narrow set of biological parameters – such as the potential for the GM mosquito to transmit disease or the potential of the mosquitoes’ new proteins to trigger an allergic response in people – and neglect other important biological, ethical and social considerations.

To address these shortcomings, the Institute for Sustainability, Energy and Environment at University of Illinois Urbana-Champaign convened a “Critical Conversation” on GM mosquitoes. The discussion involved 35 participants from academic, government and nonprofit organizations from around the world with expertise in mosquito biology, community engagement and risk assessment.

A primary takeaway from this conversation was an urgent need to make regulatory procedures more transparent, comprehensive and protected from biases and conflicts of interest. In short, we believe it is time to reassess risk assessment for GM mosquitoes. Here are some of the key elements we recommend.

The mosquito spray OFF! was handed out for free at the Zika Virus Town Hall Meeting at Waverly Condominiums in 2016. Jeffrey Greenberg/Universal Images Group via Getty Images

Steps to make risk assessment more open and comprehensive

First, an official, government-funded registry for GM organisms specifically designed to reproduce in the wild and intended for release in the U.S. would make risk assessments more transparent and accountable. Similar to the U.S. database that lists all human clinical trials, this field trial registry would require all technology developers to disclose intentions to release, information on their GM strategy, scale and location of release and intentions for data collection.

This registry could be presented in a way that protects intellectual property rights, just as therapies entering clinical trials are patent-protected in their registry. The GM organism registry would be updated in real time and made fully available to the public.

Second, a broader set of risks needs to be assessed and an evidence base needs to be generated by third-party researchers. Because each GM mosquito is released into a unique environment, risk assessments and experiments prior to and during trial releases should address local effects on the ecosystem and food webs. They should also probe the disease transmission potential of the mosquito’s wild counterparts and ecological competitors, examine evolutionary pressures on disease agents in the mosquito community and track the gene flow between GM and wild mosquitoes.

To identify and assess risks, a commitment of funding is necessary. The U.S. EPA’s recent announcement that it would improve general risk assessment analysis for biotechnology products is a good start. But regulatory and funding support for an external advisory committee to review assessments for GM organisms released in the wild is also needed; diverse expertise and local community representation would secure a more fair and comprehensive assessment.

Furthermore, independent researchers and advisers could help guide what data are collected during trials to reduce uncertainty and inform future large-scale releases and risk assessments.

The objective to reduce or even eliminate mosquito-borne disease is laudable. GM mosquitoes could prove to be an important tool in alleviating global health burdens. However, to ensure their success, we believe that regulatory frameworks for open, comprehensive and participatory decision-making are urgently needed.

This article was updated to correct the date that Oxitec withdrew its OX513 trial application to 2018.

[Deep knowledge, daily. Sign up for The Conversation’s newsletter.]

Brian Allan, Associate Professor of Entomology, University of Illinois at Urbana-Champaign; Chris Stone, Medical Entomologist, University of Illinois at Urbana-Champaign; Holly Tuten, Vector Ecologist, University of Illinois at Urbana-Champaign; Jennifer Kuzma, Goodnight-NCGSK Distinguished Professor, North Carolina State University, and Natalie Kofler, Levenick Resident Scholar in Sustainability, University of Illinois at Urbana-Champaign

This article is republished from The Conversation under a Creative Commons license. Read the original article.

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Gary Pearse
June 6, 2020 10:27 pm

GM to make it impossible for mosquitos to carry viruses, which they refer to once, is the way to go if this is a choice. Making female offspring die is a no-no! This would effect other creatures like frogs , toads, bats, birds, spiders(?), geckos, lizards, fish, dragon flies… which eat mosquitos.

Wiping out the actual mosquitos is the linear thinking Luddite type of idea, like importing leopards to control your rabbit problem.

W G Lowe Jr
Reply to  Gary Pearse
June 6, 2020 11:51 pm


Reply to  W G Lowe Jr
June 7, 2020 1:26 pm

You could make a good movie about how a gentically engineered mosquito, designed to have infertile offspring, transfers that gene modification to people by biting them and….

Pop Piasa
Reply to  DMacKenzie
June 7, 2020 2:56 pm

…and offspring are cloned from modeled, artificially constructed zygotes?

Reply to  Gary Pearse
June 6, 2020 11:53 pm

Exactly what I was thinking. The food chain of all creatures is interlinked.

Reply to  Gary Pearse
June 7, 2020 1:18 am

Unlike flies and many other insects, mosquitoes do not play an important role in nature. They are a minor part of the food chain for some fish and aquatic animals – but only a small part. They don’t do important jobs like flies do – eg breaking down dead bodies of animals. They literally have no benefit in nature. They only cause harm. The world would be a better place if all disease carrying mosquitoes were eradicated.

Reply to  ggm
June 7, 2020 3:50 am


I’m not sure that’s correct. Bats tend to predate heavily on mosquitoes.

After all, spreading diseases places bounds on population growth of large animals like humans! For obvious reasons, said large animals don’t like it, but it is a valid link in food webs.

Gary Pearse
Reply to  Disputin
June 7, 2020 10:17 am

Swallows and bats, lizards, geckos (I’ve enjoyed watching these little guys in a number of African countries scuttle out from behind a picture on the wall or curtain and pick of mosquitoes, flies, moths, etc)

Reply to  ggm
June 7, 2020 4:26 am

Maybe the adult mosquitoes are not on anyone’s dinner plate, but mosquito larvae are a favorite of many fish and other small aquatic predators.

Messing with something you don’t fully understand, like life, is inherently dangerous!
The road to hell is paved with good intentions.

Stay sane,

Reply to  ggm
June 7, 2020 5:30 pm

Go to the Barren Lands of Canada and repeat that.
The Boreal Forest Lakes and the Barrens depend on mosquitos.

Eric Vieira
Reply to  Gary Pearse
June 7, 2020 3:25 am

There are other non-disease carrying mosquito species as well as other insects out there that will fill the gap. Often, the problematic species (Aedes aegypti, Aedes albopictus) aren’t supposed to be in this location in the first place (invasive species), so getting rid of them locally shouldn’t be a problem. It certainly is better for the ecosystem, than spraying insecticides which kill everything…

Reply to  Gary Pearse
June 7, 2020 3:56 am

There are lots of mosquito species that are not a problems. A few species however are some of the biggest threats to humans on the planet.

Screw worm and fruit flies come to mind as species controlled by releasing millions (billions?) of sterilized males. This was done via radiation in the days before GM.

I don’t recall hearing of any ecological collapse because some other species were deprived of screw worms or fruit flies as a food source.

michael hart
Reply to  Gary Pearse
June 7, 2020 5:53 am

I expect the effect will be localized, just as is that of DDT. As with DDT that’s one side of the cost-benefit equation that I, for one, am quite happy to accept.

My main concern is that it just may not work very well, or at least not work very well in a cost-effective manner. I’ve read of many similar such experiments in the past. What happened to them? They obviously weren’t successful enough to be taken up on a large scale.

Clyde Spencer
Reply to  michael hart
June 7, 2020 5:43 pm

For male-sterilization to work, the females of a species must only mate once. These programs have actually been quite successful in many places that were formerly plagued by the flies.

Reply to  Gary Pearse
June 7, 2020 8:29 am

Mosquitoes certainly do NOT constitute a loss of food that can do nything more than slightly reduce the affected populations, if that. Claims like these are pure speculation and have not provided any evidence that mosquitoes protein is even importanrt for the predators.
Likewise, many are incapable of providing any solid evidence that eradicating mosquitoes
would be of any harm. Thousands of species come and go as it is. The fear that because a human has protuced a gene mutation , which could just as easilly have occurred in nature, is just plain silly. Stop defending killer insects, you morons

Gary Pearse
Reply to  ColMosby
June 7, 2020 10:32 am

Col: bats eat their own weight in mosquitos ~1000\hr and dragonflies larva in water feed hugely on mosquito larva, ditto small fish and minnows. This insect is a very large percentage of all insects.

John Tillman
Reply to  Gary Pearse
June 7, 2020 12:21 pm

Mosquitoes aren’t a single insect. They’re about 3500 out of 5.5 million known insect species, 1.5 million of which are beetles.

John Tillman
Reply to  Gary Pearse
June 7, 2020 11:53 am

No mosquito-dependent vertebrate species will miss Aedes egypti or any other disease vector. There are over 3500 mosquito species in the world.

Reply to  Gary Pearse
June 7, 2020 2:05 pm

Rather than GM the mosquitos, why not control the numbers drastically by releasing infertile males – this has been developed and tested. – We could drop the world population of these insects in a controlled way. You will also not be maintaining a GM species in the environment.

Could any species survive without Mosquitos ?

Unfortunately all but one species bitten by these creatures do not have a vote, but if they did – and understood it – then I suspect they would approve their total extermination 🙂

John Tillman
Reply to  Gary Pearse
June 7, 2020 4:40 pm

The dengue and yellow fever-carrying species or at least subspecies of Ae. aegypti owes its existence to humans, so why not eradicate it?

Human impacts have shaped historical and recent evolution in Aedes aegypti, the dengue and yellow fever mosquito

Gary Pearse
Reply to  John Tillman
June 10, 2020 6:39 am

What’s your bet that other ‘benign’ varieties wouldn’t step up and provide hosts for the diseases? BTW John, I wasn’t arguing numbers of species, I was talking tonnage of these global pests.

John Tillman
Reply to  Gary Pearse
June 11, 2020 4:14 pm

There might well arise new blood-sucking vectors of pathogens. How is that an argument against wiping out the vectors we know now?

IMO odds of new vectors are low, since ridding us of vectors also extinguishes their pathogens.

John Tillman
Reply to  Gary Pearse
June 7, 2020 4:42 pm

Evolution of mosquito preference for humans linked to an odorant receptor

David Long
June 6, 2020 11:38 pm

Aedes aegypti, the yellow fever mosquito, is a mosquito that can spread dengue fever, chikungunya, Zika fever, Mayaro and yellow fever viruses, and other disease agents. (Wikipedia)
The method is species specific, there are lots of other species for critters to eat.
Kill ’em.

Reply to  David Long
June 7, 2020 3:10 am

And they can ruin a good backyard bbq. They gotta go.

We can call it ‘assisted evolution’ or something.

Reply to  David Long
June 7, 2020 7:36 am

David Long, agree w/you. Get rid of the ticks and fleas too.

Reply to  David Long
June 7, 2020 8:37 am


Thanks, David.

The few really bad mosquito girls spread the severe medical problems, huh? My unnerstanning is that the males eat and drink on your lawn or garden cover or…… So a process to reduce the female population sounds good, but seems we could be species specific if we are messing about with DNA of specific species.

That being said, our purple and bats are zipping about here along the Gulf Coast, and those pesky biters are an important part of the ecology.

Gums sends…

June 6, 2020 11:56 pm

I got Ross River Virus from mosquito bites. The absolute discomfort from this for many years is a real pain. Over 20 years ago. I could care less about frogs and such. Destroy every mosquito and I’ll be happy.

Steven Miller
Reply to  Alex
June 8, 2020 8:10 am

Mosquitos are by far the most deadly animal to humans in the world. Approximately a million people a year die from mosquito born illnesses, most of them children. Are we going to object to the extermination of lice and scabies as well on this forum. There are some forms of life on this planet who deserve extinction.

June 7, 2020 12:16 am

Anyone Care to take bets against how fast this “mutation” will be selected against? Or worse both by the viruses and the mosquitos mutating.

Reply to  SL
June 7, 2020 6:23 am

Life finds a way

June 7, 2020 12:49 am

regulatory and funding support for an external advisory committee to

Grab your wallets. By external advisory committee they mean a committee made up of themselves, funded by you. The committee will do the same work with the same data that the tax payer has already funded. They just want themselves to be paid to do it again.

If, with all their vaunted expertise on the matter, they had a legit complaint about the science, they could just say so.

June 7, 2020 1:18 am

If plagues have been spread by fleas what’s to stop someone from working out a deliberate way for mosquitoes to spread other such viruses?

Joel O’Bryan
Reply to  Megs
June 7, 2020 2:20 am

The plague generally refers to the bacterium Yersinia pestis, of bubonic plague infamy. So not a virus. Getting viruses to use other nonhuman hosts likely has significant barriers. Lice carry Typhus bacterium Rickettsia prowazekii. Antibiotics such as doxycycline are curative for both typhus and the plague.

June 7, 2020 1:19 am

We get enough wind here in Tejas, it blows them all up into Kansas; what is the purpose of this ‘drill’ again?

Joel O'Bryan
June 7, 2020 1:42 am

Aedes aegypti is one of two Aedes genus species that transmit those viruses in the US and North America in general, Aedes albopictus the other. By definition, these 2 species don’t cross breed.

Aedes albopictus is also an efficient vector for those same viruses. AKA, the Asian tiger mosquito. Daytime biters. And the relevant arbovirus vector in the US for the mentioned viruses, more so than Ae. aegypti for the US.

Not sure how this GMO Ae. aegypti will affect Ae. albopicuts.

John Tillman
Reply to  Joel O'Bryan
June 7, 2020 12:24 pm

If the control technique works with Aedes aegypti, they can move on to Ae. albopicuts.

Clyde Spencer
Reply to  Joel O'Bryan
June 7, 2020 5:50 pm

If the two different species don’t interbreed, then they should be no impact on Ae. albopicuts.

June 7, 2020 1:58 am

Murder hornets are so last week.

John Grosse
June 7, 2020 3:54 am

How long will it take for these GM mosquitoes to select and mate with females that can spread dengue fever, chikungunya, Zika fever, Mayaro and yellow fever viruses, and other disease agents to make a difference. Years? Decades? And in the meantime, you can’t use insect repellent to kill mosquitoes. So the GM mos will eventually die out and you are back to square one!!

June 7, 2020 4:04 am

Here is a similar argument:

“In a paper just published in the journal BioScience, two Oregon State University researchers argue that human-caused extinction of the tsetse fly would be unethical”

It is easy to argue in favor of the tsetse fly when you live in Oregon.

Ed MacAulay
Reply to  ferdberple
June 7, 2020 4:34 am

So sad that science and medicine have caused extinction of the smallpox virus, and are trying to do the same for the polio virus. Except for some secret lab preserved samples?

With the mosquitoes, at least this sterility trait will not be passed on to offspring. As they die out in one area, I am sure the wind will blow new recruits in to replace the loss populations.

Paul C
Reply to  Ed MacAulay
June 7, 2020 5:39 am

Yes, it is interesting that the aim is for large scale releases to create only a temporary collapse in the local population of a foreign species. Eradication would be so much better in such cases.

John Tillman
Reply to  Ed MacAulay
June 7, 2020 5:19 pm

Also, RIP rinderpest virus, now eradicated, but which in its heyday wiped out African cattle, opening the way for tsetse flies to reoccupy vast swaths of Africa, making traditional pastoralism impossible there.

Good riddance!

John Tillman
Reply to  Ed MacAulay
June 7, 2020 5:21 pm

PS: Rinderpest virus was the ancestor of human measels pathogen.

With measles vaccine, we might be able to eradicate that disease, as well.

John Tillman
Reply to  ferdberple
June 7, 2020 1:48 pm

Won’t be easy to wipe out the dozens of species and subspecies of Genus Glossina. They fourished from the late 19th century, invading or reinvading land which had been cattle range after the rinderpest outbreak killed off native and imported livestock. Wild animals replaced them, which had immunity to tsetse-borne diseases.

BTW, tsetse files are rare, in bearing live young.

John Tillman
Reply to  John Tillman
June 7, 2020 1:49 pm

Oops! The dread K-word again.

Paul C
June 7, 2020 5:34 am

I see the atricle uses the ubiquitous conflation of using “Government funded” when they mean “Taxpayer funded” – I am sure a global (voluntary – best practice) registry could have been set up for less than the cost of the conference if that was all they were aiming at. It would then quickly become de facto compulsory if the regulator in a jurisdiction simply requires the trial applicant to have registered the proposal prior to application for the permit . Access to a free registry could easily be adopted by all institutions involved in such a specialised discipline, and become a useful resource to them (and the public) to find links to past, current and proposed trials. The demand to involve government implies compulsion, and no doubt regulators would insist on a fee for registration. The regulatory rent-seekers would inevitibly expand the scope of any simple registry to include oversight, and further fees.

June 7, 2020 6:37 am

Is this a Monty Python sketch?

Can they do silly walks?

June 7, 2020 6:47 am

We can probably live without mosquitoes. The real question is what will fill the mosquito vacuum? Nature will fill it with something. Is that likely to be better or worse?

John Tillman
Reply to  Dave
June 7, 2020 2:58 pm

Blood-sucking or -feeding insects evolved at least six times in the Mesozoic Era, let alone ticks and other biting arthropods. Mosquitoes might get replaced, but would the pathogens which they carry as well?

June 7, 2020 6:52 am

All for it, cannot think of any time in the historical record where introducing a genetically modified non-seed organism into the wild has had any bad outcomes.

Reply to  dmacleo
June 7, 2020 8:31 am

….has NOT had any bad outcomes.

June 7, 2020 8:06 am

Did Bill G remember to put the right vaccine in them?

June 7, 2020 9:43 am

From my limited understanding, Mozzy’s bite to draw a protein in the blood that they themselves cannot produce for egg formation.

May I suggest instead, working on introducing that gene/genes into the Mozzy world, and maybe eventually they would have no need for blood?

John Tillman
Reply to  DeNihilist
June 7, 2020 11:56 am

Female mosquitoes use a variety of amino acids from their blood meals, but some more than others. They, like us, have essential amino acids, which they must get from their diet.

It’s not a question of a single gene.

John Tillman
Reply to  DeNihilist
June 7, 2020 11:58 am

And in case your interested in genetic vector control:

Disruption of Mosquito Blood Meal Protein Metabolism

John Tillman
Reply to  John Tillman
June 7, 2020 12:12 pm

You’re. Dreaded autofill strikes again.

John Tillman
June 7, 2020 12:06 pm

Mosquito blood-sucking evolved in the Cretaceous, but now there’s a species evolving a non-biting lifestyle:

Evolutionary transition from blood feeding to obligate nonbiting in a mosquito

With their prodigious populations and short generation times, mosquitoes can evolve rapidly when under selective pressure to do so. The malaria vector Anopheles gambiae is currently undergoing speciation into the M(opti) and S(avanah) molecular forms. Consequently, some pesticides that work on the M form no longer work on the S form.

Widespread divergence between incipient Anopheles gambiae species revealed by whole genome sequences

June 7, 2020 12:13 pm

Shades of Love Bugs..
(rumor is that Love Bugs imported themselves) but UF will forever be blamed, and I am sure funding has suffered because of this. Oxitec personnel beware!

(I, also, decry any attempt to place a block in a normal natural food chain.)

John Tillman
Reply to  Enginer01
June 7, 2020 1:25 pm

Humans have long attempted to block the natural food chain, but have also augmented it, as in the cases of rats, coyotes and whitetail deer. Our antibiotics block the natural food chains of many bacterial pathogens, for instance. Wolf bounties of old enabled our domestic livestock to survive their wild predators. We used to hunt cougars, but now effecctively can’t, so they hunt us and our animals.

June 7, 2020 5:34 pm

If the geniuses at work here are modern “scientist” I fear the results.
On one hand we must save the planet,yet we seek to exterminate a species?
And I am quite sure they lack sufficient understanding of the eco system they seek to “improve”.

Mosquitos are Gods way of making even the most miserable miscreant feel wanted.
Black flies are so you can really feel the love.

June 7, 2020 7:38 pm

The Wolbachia program appears much more nuanced. If you do a quick google, it should show up. They’ve been testing in Queensland, Australia (and elsewhere) with very positive results.

June 8, 2020 4:15 am

I’m all for it. The world will get along just fine without mosquitoes. Sooner the better.

June 8, 2020 8:04 am

What could possibly go wro…

June 8, 2020 9:02 am

These exact same mosquitoes have been used in Brazil for 4-5 years now with excellent insect control results. Specifically designed for dengue control, but also quite important when the same species of mosquito was found to be involved in Zika transmission. I don’t have anything more than anecdotal information that dengue cases were down.

The application for the Florida trial was made more than 10 years ago – before trials were started in Brazil. This trial has been reviewed out of its socks. Not sure you can call this jumping the gun!

June 8, 2020 9:46 am

For all those who apparently fear that these GM mosquitos should spread sterility to other species, please note that these mosquitos have a GENE, that is lethal in female mosquitos of the same species.

They will no more kill females of other species than eating mule meat will cause sterility in other species just because mules are sterile.

Filippo Turturici
June 9, 2020 2:58 am

I admit it: I totally hate mosquitos. Give me a good reason not to exterminate them all – really – and I will give it up; but, in this article, I saw nothing, just a list of “what if” without even a fictional answer. If erasing mosquitos will not impact the ecosystem, I really do not get the point here – apart from possible economical considerations about free market of mosquito extermination.

John Tillman
June 9, 2020 11:58 am

Mosquito larva-eating mosquito:

Use as a control agent has produced mixed results.

John Tillman
Reply to  Charles Rotter
June 11, 2020 4:16 pm

Go to your room!

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