The why behind every place

Nature and geographyIceland

Iceland had no mosquitoes. Until October 2025

For centuries, Iceland was one of the last places on Earth without mosquitoes. In 2025, the first ones turned up. Why it took so long, and what it means.

By

7 min read

Small black houses by a grassy lake in Arnarstapi, Iceland
Photo by A J. on Unsplash

For all of its recorded history, Iceland had no mosquitoes. The country has lakes, wetlands and long summer days, exactly the kind of place mosquitoes usually thrive, yet alongside Antarctica it was one of the only regions on the planet without a single record of one. That changed in October 2025, when three mosquitoes turned up on a farm north of Reykjavík.

The find was confirmed by the Natural Science Institute of Iceland. Antarctica is now the only place in the world believed to be mosquito-free.

A ribbon soaked in red wine

The mosquitoes were found by Björn Hjaltason, an insect enthusiast, on a farm in Kjós, north of Reykjavík. He hangs ribbons soaked in red wine to attract moths. At dusk on October 16, he spotted a strange fly on one of them. “I immediately suspected what was going on and quickly collected the fly,” he told the Icelandic broadcaster RÚV. It was a female.

He later caught two more and handed all three to the authorities. Tests showed they were two females and one male of the species Culiseta annulata, and the institute announced the discovery on October 21.

Why they never made it before

Mosquitoes had been found on planes landing in Iceland before, and none of them ever started a population. What kept them out, as far as scientists can tell, was the climate itself.

Icelandic winters are milder than the latitude suggests, but they’re unstable. According to Science News, the island freezes and thaws several times a year. Those swings can threaten adult mosquitoes that leave their shelter during a thaw and get caught by the next cold snap, as well as species that spend the winter as eggs or larvae. Some species are sensitive enough to those swings that they never get established.

What changed

Two things, researchers say. The first is transport: the Icelandic institute believes the mosquitoes hitched a ride in freight, as trade and travel keep growing. The second is climate. The Arctic is warming roughly four times as fast as the global average, according to Science News, and Iceland saw record heat in 2025.

The species that arrived helps too. Culiseta annulata is a large mosquito, common across Europe, including Sweden and Finland, and used to the cold. Adults sit out the winter in basements, sheds and caves, which may shield them from the swings that stopped other species.

In November 2025, scientists said it was too early to tell whether those few individuals would survive the winter and breed. The fact that both males and females were found suggested they could. But as ecologist Kelsey Lyberger of Arizona State University pointed out, luck plays a part too: if those few individuals didn’t survive or didn’t breed, the population would never form.

And in 2026? The mosquitoes vanished

The answer began to emerge the following summer. On September 18, 2026, the Icelandic news site Vísir reported that the mosquito “seems to have evaporated”: not a single one was seen during the summer of 2026.

The report also gave a fuller picture of 2025 than was known at the time of the discovery. According to biologist Gísli Már Gíslason, professor emeritus, mosquitoes were found at three places in Iceland that year, and they belonged to two species. The first turned up in Kollafjörður and Kjós. The second was found in a horse stable in Ölfus, in the south of the country.

The disappearance wasn’t just luck. The Natural Science Institute, through entomologist Matthías Alfreðsson, tried to wipe the insect out. At the Ölfus stable, a silicone-like layer was applied over the manure pit beneath the stalls, suffocating the larvae. The traps stopped catching mosquitoes. In Kjós there were no new records either, and searches for larvae in nearby ponds found nothing.

Gíslason says he’s hopeful but won’t call it over yet. He’d rather wait until late autumn before saying the mosquito is gone for good.

Should anyone worry?

Not much, for now. Culiseta annulata bites, but according to the Icelandic institute it doesn’t carry known infections where it lives. A 2017 study described it as a biting nuisance rather than a deadly foe. That distinction matters: there are more than 3,000 mosquito species worldwide, and some spread serious diseases such as malaria, dengue and West Nile virus. According to the Icelandic institute, the mosquito is just one of several new insect species found in the country in recent years, as the climate warms and international transport grows.

What catches scientists’ attention is the signal. For entomologist Jessica Ware of the American Museum of Natural History, the fact that mosquitoes never showed up in the whole history of human travel to the island, and now have, suggests the shift is climate-driven. Other insects, such as dragonflies that prey on mosquitoes, may follow the same path.

The insect that actually bites: lúsmý

Summer visitors to Iceland have a far more real nuisance to worry about than mosquitoes. It’s lúsmý, a tiny biting midge.

It has spread fast. According to a Gallup survey cited by Vísir, almost four in ten Icelanders think they were bitten by lúsmý in summer 2026, most of them in the south. When the survey was first run, in 2019, the figure was 14%. The year before, it was 32%.

Lúsmý lives mainly in wooded areas, sheltered from the wind. According to Gíslason, bites happen mostly around summer-house areas and campsites, where there are trees. Out in open country, people hardly get bitten.

If you’re visiting

  • Don’t change your plans because of mosquitoes. The 2025 records were few, and none turned up in summer 2026.
  • Worry more about lúsmý. At campsites and summer-house areas with trees, repellent and long sleeves help.
  • In open country, bites are much less likely. Lúsmý stays in the woods, out of the wind.
  • Curious? Follow the Icelandic institute. It confirms every new record in the country.

FAQ

Are there mosquitoes in Iceland?

The first ones were found in 2025, at three places in the country. None were seen in summer 2026, after the Icelandic institute worked to eliminate them.

Which mosquito was found in Iceland?

The first one identified was Culiseta annulata, a large, cold-tolerant species common in Europe. According to Vísir, a second species was found in a horse stable in Ölfus.

Do Iceland’s mosquitoes carry disease?

Culiseta annulata bites, but it doesn’t carry any known infections in the regions where it lives, according to the Icelandic institute.

What is lúsmý?

It’s a tiny biting insect, a type of biting midge. It has spread across Iceland in recent years and is found mainly in wooded areas.

Iceland is already a place where the sun and the clock don’t line up, as the post on why the country hasn’t changed its clocks since 1968 explains. Now it has lost one of its most famous quirks as well.

Sources

Keep reading