Mosquitoes make surprise appearance in Iceland, sparking climate alarm

In a development that has caught both scientists and residents off guard, mosquitoes have been discovered in Iceland for the first time in recorded history.

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The insects appeared this month in a quiet valley north of the capital, putting an end to Iceland’s long-held reputation as one of the few places on Earth free of these biting pests.

The discovery came after a local insect hobbyist, while setting out traps designed to attract moths, found what he believed to be an unusual fly. On further inspection it turned out to be a mosquito, and two more of the insects—one male and two females—were collected soon afterwards in the same location. The specimens have been identified as belonging to a species known for its hardiness in cold conditions.

Until now, the island nation had avoided a mosquito population despite offering many of the typical breeding habitats—bogs, marshes, ponds and shallow water bodies. What has changed, experts believe, is the climate. Iceland’s environment is warming at a rapid pace, and longer periods of mild weather may be creating conditions suitable for mosquitoes to survive and reproduce.

One of the factors that historically kept mosquitoes away from Iceland is its seasonal pattern of freezing and thawing.

Normally, shallow waters would freeze in winter, then thaw briefly, then freeze again. That erratic cycle disrupts the life cycle of the mosquito: eggs or larvae may hatch only to be killed when temperatures drop again before they mature. The newly recorded species, however, has a known capacity to survive colder climates by overwintering in sheltered places such as animal barns or basements.