Pesky conspiracy theory about GMO mosquitoes is back. Here’s why they aren’t in Ohio.

Itching to blame someone for pesky mosquitoes?

One social media post proposes a culprit: A video showing planes flying over the Ohio River, it says, is evidence the government is dumping genetically modified mosquitoes into the air.

"Modified mosquitoes have officially made it to Ohio," read text on an image of a two-slide Instagram post. In one slide, a video shows three planes trailing smoke.  In another slide, Ohio is highlighted in red on a U.S. map and an illustration shows a mosquito being injected with a syringe. 

A caption with the post had numerous hashtags, including #gmomosquitoes and #billgatesisevil. A similar but longer YouTube video linked in the caption includes a news clip about recent malaria cases found in Alabama and New York.

This Instagram post was flagged as part of Meta’s efforts to combat false news and misinformation on its News Feed. (Read more about our partnership with Meta, which owns Facebook and Instagram.)

The video appears to have originated Sept. 3 on TikTok by a user who set it to ominous music and said it was taken Sept. 3 on the Ohio River in the region of Cincinnati, Ohio-Newport, Kentucky. That post did not mention mosquitoes, although some commenters speculated about them. We found multiple other social media posts using the video to baselessly claim that mosquitoes were being released from the planes.

There was a daylong celebration called Riverfest on Sept. 3, with events on both sides of the Ohio River that culminated in a nighttime fireworks show. 

Releasing mosquitoes on an unsuspecting crowd was not part of the event, however, Newport city spokesperson Lauren O’Brien told PolitiFact. The flyover was part of the event, and it happens every year, the spokesperson said.

One plane that participated in flyovers during Riverfest was from the Tri-State Warbird Museum in Batavia, Ohio. The museum is a not-for-profit organization dedicated to preserving military aircraft and honoring military and historic aviation, particularly during World War II.

The museum’s B-25 plane — and T-34 planes owned by others — participated in the Lunken Airport Days event that was taking place the same weekend at a nearby Cincinnati municipal airport. That event displayed historic aircraft and allowed attendees to book rides on planes and helicopters. 

This YouTube video shows the Tri-State Warbird Museum’s B-25 and other planes participating Sept. 3, 2023, in the Lunken Airport Days in Cincinnati. 

The planes "left a trail of smoke oil," not mosquitoes, said Stephanie Felts, director of education and public programming at the museum.

Felts, who called the mosquito claim "baseless," pointed us to an article about smoke oil, which is commonly used by planes to create trails during airshows.

Barry Munden, a webmaster with the Cincinnati Warbirds, a nonprofit group that preserves military aircraft and hosted the Lunken event, said smoke generators are common in aerobatic aircraft so crowds and other planes can see them from a distance.’

"They work by releasing a small amount of paraffin-based mineral oil into the flow of the exhaust, where the heat from the exhaust turns it to smoke," said Munden. He said the oil itself is nontoxic and biodegradable. 

"I'm not sure what any of that has to do with mosquitos, though," Munden said. "Mosquitos are terrible flyers, cannot hold formation in even light winds and typically cruise at lower altitudes."

PolitiFact has in recent months debunked similar claims that genetically modified mosquitoes were released from helicopters on crowds in Baltimore, are responsible for recent cases of malaria in the U.S., and that modified ticks funded by billionaire philanthropist and Microsoft Corp. co-founder Bill Gates are responsible for meat allergies in the U.S.

A company called Oxitec genetically modifies mosquitoes to control the invasive Aedes aegypti mosquitoes (yellow fever mosquitoes) in the U.S.

But it does not release mosquitoes by planes, helicopters, or any sudden mass release, said Jamie Lester, an Oxitec spokesperson. And the species, which can travel only about 100 meters, does not carry malaria.

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Oxitec’s program is the only genetically modified mosquito program the Environmental Protection Agency has approved in the U.S. The EPA has approved Oxitec testing only in parts of Florida and California, but release of the mosquitoes has taken place only in Florida. Oxitec is in its third mosquito season in the Florida Keys since 2021 and expects to release fewer than 5 million genetically modified mosquitoes there this year.

It has no program in Ohio or any other U.S. state.

"They are released gradually over a period of days after adding water to a small box," Lester said, providing a link to an image of the boxes. "This means that mosquitoes cannot be released in the kind of quantities claimed in this video."

Oxitec scientists modify male mosquitoes — which do not bite humans — with a self-limiting gene, which they pass on to female mosquitoes. The gene overproduces a protein, which disrupts the offspring’s development and ability to grow into an adult.

The Bill & Melinda Gates Foundation didn’t fund any of Oxitec’s U.S. mosquito work, though it has given money for the company’s anti-malaria efforts in other countries.

A spokesperson for the Ohio Department of Health said it is not aware of any current mosquito-release programs in the state. The spokesperson said any program involving genetically modified mosquitoes would need EPA approval and would likely not involve aircraft.

The EPA has also approved a technique by a company called MosquitoMate, which infects male tiger mosquitoes (Aedes albopictus) with Wolbachia, a natural bacteria that is present in many insect species, including mosquitoes. When those males mate with females, they pass along the infection, which causes the female to lay eggs that do not hatch, the company said.

Those mosquitoes are not genetically modified, and although MosquitoMate is approved for use in Ohio, the company does not currently release mosquitoes there, said Stephen Dobson, founder and chief executive of MosquitoMate.

The company operates primarily in Kentucky and doesn’t release mosquitoes by planes or helicopters. It generally does so by hand around private homes and businesses, although it has released them from vans in the past, Dobson said.

Dobson said "to have enough mosquitoes to put a line in the sky like that" seen in the Instagram video, would require "billions of mosquitoes."

An Instagram post claimed that genetically modified mosquitoes were released in Ohio. As evidence, it showed video of airplanes flying over an event called Riverfest in Cincinnati and Newport, Kentucky, along the Ohio River.

The planes were part of the annual event, a Newport spokesperson said. The only program that releases genetically modified mosquitoes in the U.S. has done so only in the Florida Keys. There are no mosquito-release programs in Ohio.

We rate the claim False.