Scientists Find New Invasive Mosquito Species In Florida

Mar 16, 2021
Originally published on March 16, 2021 1:52 pm

Scientists have identified a new species of mosquito in Florida. I's called Aedes scapularis. Lawrence Reeves, an entomologist and research scientist with the University of Florida, identified them among mosquitoes he collected near Everglades National Park in 2019.

Collecting mosquitoes is easy, he says, using traps baited with dry ice. The traps emit carbon dioxide, mimicking the odors that attract mosquitoes to people and other mammals. Reeves then sifts through hundreds, sometimes thousands, of mosquitoes. He says, "You look at them under a microscope and kind of, one by one, you sift through them with forceps."

DNA analysis confirmed they were Aedes scapularis. In a follow-up study in 2020, Reeves found the species is well-established in two South Florida counties, Miami-Dade and Broward. Up to now, the mosquitoes have been found mostly in the Caribbean and Latin America. In Brazil, Reeves says, they have been found to be infected with a range of diseases, "things like Venezuelan equine encephalitis virus, yellow fever virus and a handful of others."

It's been more than a century since there was a yellow fever outbreak in the U.S. Although they're often infected it's not clear whether Aedes scapularis mosquitoes spread the disease. But as outbreaks of Zika and dengue have shown in Florida, new mosquitoes can bring new diseases. A new study Reeves co-authored with University of Florida entomologist Lindsay Campbell suggests the mosquitoes may now spread north along Florida's Gulf and Atlantic coasts.

There are other things about Aedes scapularis that are worrisome. It's a mosquito that likes going indoors and it feeds on both birds and people. Campbell says, "If you end up with a species that's capable of transmitting to [birds] and likes to also bite humans, that's the prime condition for a spillover event." Scientists believe the COVID-19 pandemic is the result of a spillover event, involving bats or another animal species.

Climate change, international travel and global trade are all factors in the spread of invasive species. According to Reeves, 10 new species of nonnative mosquitoes have been found in Florida since 2000. And more are on the way. Reeves says, "There's one in particular right now that a lot of people are worrying about, Aedes vittatus." Originally from India, the mosquito "is kind of a vector for pretty much everything we're worried about: dengue, chikungunya, Zika," Reeves says.

Aedes vittatus mosquitoes have now been found in Cuba — just 90 miles from Florida.

: 3/16/21

In the audio, and a previous version of the digital story, Lindsay Campbell says, "If you end up with a species that's capable of transmitting to bats and likes to also bite humans, that's the prime condition for a spillover event." Campbell misspoke and meant to say birds. Mosquito-borne diseases are not known to be transmitted between bats and people.

Copyright 2021 NPR. To see more, visit https://www.npr.org.

NOEL KING, HOST:

All right, now we have some news of an unwelcome scientific discovery. Researchers have identified a new species of mosquito in Florida. It's known to carry several diseases, including yellow fever. Here's NPR's Greg Allen.

GREG ALLEN, BYLINE: The life of a mosquito researcher isn't a glamorous one, but Lawrence Reeves likes it.

LAWRENCE REEVES: Yeah. I think it's really cool. I'm a big nerd for this stuff.

LINDSAY CAMPBELL: (Laughter).

REEVES: So it's really easy to collect mosquitoes.

ALLEN: Reeves is a research scientist with the University of Florida. And his collaborator is entomologist Lindsay Campbell. One way you collect mosquitoes is with a vacuum.

(SOUNDBITE OF VACUUM)

ALLEN: In a video he recorded, Reeves traipses through undergrowth.

REEVES: It's kind of like "Ghostbusters." You go around in the field sucking up mosquitoes with these vacuums. And then you end up with a bag of hundreds or thousands of mosquitoes that you have to sift through to identify.

ALLEN: Sifting through mosquitoes collected near Everglades National Park, Reeves spotted some that he hadn't seen before. Examining them under a microscope and then analyzing their DNA, he realized they were a species new to Florida, one called Aedes scapularis. Up to now, they've been found mostly in the Caribbean and Latin America. In Brazil, Reeves says, the mosquitoes have been found to be infected with a range of diseases.

REEVES: Things like Venezuelan equine encephalitis virus, yellow fever virus and a handful of others.

ALLEN: It's been more than a century since there was a yellow fever outbreak in the U.S. And although they're infected, it's not clear if Aedes scapularis mosquitoes spread the diseases. But as outbreaks of Zika and dengue have shown in Florida, new mosquitoes can bring new diseases. The species is already established here, and a study suggests it may spread north along Florida's Gulf and Atlantic coasts.

And there are other things about Aedes scapularis that are worrisome. It's a mosquito that likes going indoors and feeds on both wildlife and people. Campbell says that's not good.

CAMPBELL: If you end up with a species that's capable of transmitting to bats and likes to also bite humans, that's the prime condition for a spillover event.

ALLEN: Scientists believe the COVID-19 pandemic is a result of such a spillover event involving bats or another animal species. Climate change, international travel and global trade are also factors. Ten new species of non-native mosquitoes have been found in Florida since 2000. And Reeves says more are on the way.

REEVES: There's one in particular right now that a lot of people are worrying about, Aedes vittatus, which is kind of an old-world vector for pretty much everything that we're worried about - dengue, chikungunya, Zika.

ALLEN: Originally from India, Aedes vittatus mosquitoes have now been found in Cuba, just 90 miles from Florida.

Greg Allen, NPR News, Miami.

[POST-BROADCAST CORRECTION: In this report, Lindsay Campbell says, "If you end up with a species that's capable of transmitting to bats and likes to also bite humans, that's the prime condition for a spillover event." Campbell misspoke and meant to say birds. Mosquito-borne diseases are not known to be transmitted between bats and people.]

(SOUNDBITE OF MUSIC) Transcript provided by NPR, Copyright NPR.