Yes, Greenland has mosquitoes. Their presence is a brief, seasonal event across the tundra that marks the short Arctic summer. For a few intense weeks, typically in June and July, mosquitoes become a dominant feature of the landscape, affecting both wildlife and people. They vanish with the return of colder temperatures.
The Unique Conditions for Arctic Mosquitoes
The primary species, the Arctic mosquito (Aedes nigripes), has adapted its life cycle to the harsh environment. Its eggs are laid in the soil of dry pond beds and can withstand being frozen solid through the long winter. This allows the population to survive until the next summer.
When the spring sun returns, it melts the snow and the upper layer of permafrost, creating countless shallow, temporary ponds. These stagnant pools are the nurseries for mosquito larvae, which hatch from the overwintering eggs as soon as the ice melts. The larvae feed on organic matter in the ponds, developing quickly over two to three weeks before emerging as adults.
The Summer Mosquito Swarms
The adult mosquito emergence results in immense swarms that can cloud the air. These swarms are aggressive in their search for a blood meal, which females require to produce eggs. Only a small fraction, perhaps 12 to 15 percent, of females successfully find a blood meal, driving their intense behavior. With limited large animal hosts, the swarms converge on any available source.
This event has a significant impact on the region’s wildlife, especially caribou. The mosquito emergence often coincides with the caribou calving season, when herds are less mobile and calves are vulnerable. The harassment from biting swarms can be severe enough to disrupt grazing patterns, forcing caribou to expend energy seeking refuge instead of feeding. This can lead to lower body weight, reduced reproductive success, and sometimes the death of young calves.
Influence of a Warming Climate
A warming climate is altering the dynamics of mosquito populations in Greenland. Rising Arctic temperatures lead to earlier spring thaws, causing mosquito eggs to hatch sooner. Warmer water temperatures also accelerate the larvae’s growth, shortening their development time by about 10% for every one-degree Celsius increase.
While faster development can increase exposure to predators, it reduces the time spent in the vulnerable larval stage. This could boost their survival-to-adulthood probability by over 50% with a two-degree Celsius temperature rise, leading to larger and more prolonged mosquito seasons. Continued warming may also allow new mosquito species to establish themselves in Greenland, introducing new ecological pressures and the possibility of mosquito-borne diseases.