Mosquitoes have been detected in Iceland for the first time, signaling a dramatic shift in the reach of one of the world’s deadliest pests.
Scientists warn that mosquitoes are effectively evolving as they expand into Iceland, surviving colder temperatures, exploiting artificial breeding sites and completing their life cycles in a region that was previously inhospitable.
These stealthy insects now pose a potential threat to humans and ecosystems that have never encountered them before. The discovery means Antarctica is the only location on Earth without the vector-carrying insect.
The first sighting was reported on October 16 by insect enthusiast Björn Hjaltason in Kjós, who posted to the Facebook group about a ‘strange fly.’
Upon collecting the insect, Hjaltason discovered it was a female mosquito. Entomologists at the Natural Science Institute of Iceland confirmed that three mosquitoes, two females and one male, were captured using red wine traps meant to attract moths.
The arrival of mosquitoes in Iceland is part of a broader pattern tied to global warming, as the country is warming, driven by a steady flow of warm air from the south.
Higher heat accelerates the development of mosquitoes, increasing survival rates and extending the mosquito season, while precipitation and humidity create ideal conditions for breeding and population growth.
Scientists cautioned that the mosquitoes’ presence could have broader ecological and health implications. Mosquitoes are vectors for deadly diseases, including malaria, dengue and chikungunya, although Iceland has no history of outbreaks.
Since arriving in Iceland, the mosquitoes, which are Culiseta annulata, have demonstrated their remarkable adaptability. Pictured is a Culiseta annulata, but not in Iceland
The exact way these pests arrived in Iceland remains unknown, but scientists suggest they may have traveled aboard ships or hidden inside transported containers, CNN reported.
It’s unclear how the mosquito arrived in Iceland, but theories include the possibility it came via ships or containers. Further monitoring will be needed in the spring to see whether the species can survive the winter and “truly become established in Iceland,” Alfreðsson said.
Since arriving, the mosquitoes, which are Culiseta annulata, have demonstrated their remarkable adaptability.
The species has exploited human-made water sources, such as buckets, rain barrels, cisterns and flowerpots, to lay eggs in a region where natural stagnant water is scarce.
Their life cycles are timed to take advantage of Iceland’s brief summer season, completing development quickly before colder months return.
Behaviorally, these mosquitoes remain stealthy and opportunistic, as they feed mainly at dawn, dusk and night, minimizing detection while reproducing effectively.
Their eggs can also survive in hidden water sources for extended periods, allowing populations to expand quietly and persist through environmental challenges.
This combination of cold tolerance, reproductive flexibility and stealthy feeding habits illustrates how the species is effectively adapting to a previously hostile ecosystem.
Scientists cautioned that the mosquitoes’ presence could have broader ecological and health implications. Mosquitoes are vectors for deadly diseases, including malaria, dengue and chikungunya, although Iceland has no history of outbreaks
The discovery means mosquitoes are now found everywhere in the world except for Antarctica
Entomologists cautioned that while Iceland currently has no mosquito-borne disease outbreaks, the insects’ ability to thrive in new environments demonstrates the potential for future health risks if pathogens are introduced.
Their presence may also alter local ecosystems, providing a new food source for predators while competing with native insects for resources.
Citizen scientists have played a key role in monitoring the spread of mosquitoes, as Hjaltason’s observation exemplified how public reporting can help track populations and alert authorities to emerging threats.
Apps like iNaturalist, Mosquito Alert, and NASA’s GLOBE Observer allow the public to contribute data on sightings, helping scientists document the insects’ ongoing adaptation and expansion.
Iceland’s mosquito invasion underscores a larger global pattern: warming temperatures are enabling mosquitoes to survive in regions once considered safe.
The species’ ability to exploit new habitats, reproduce efficiently, and survive harsher climates shows just how effectively it is evolving to colonize previously inaccessible territories.
