Greenland, a land often associated with vast ice sheets and polar bears, also hosts a surprising abundance of mosquitoes during its brief summer. These insects, primarily a single species known as Aedes nigripes, have developed remarkable strategies to thrive in this extreme environment. Their presence is not merely a minor inconvenience; it is a noticeable feature of the Arctic landscape, affecting both wildlife and human activity.
Survival in the Arctic
Greenland mosquitoes exhibit unique biological adaptations that allow them to complete their life cycle in the harsh Arctic. Their eggs are laid in shallow pools and temporary ponds formed by melted snow and ice on the tundra. These eggs possess a dormancy mechanism, known as diapause, which allows them to survive the long, freezing winter temperatures.
Once the ice melts and temperatures rise in spring, the eggs hatch into larvae, which then develop rapidly in the water. This accelerated development is a key adaptation, as the larval and pupal stages can be shortened by approximately 10% for every one-degree Celsius increase in temperature. After a few weeks, these larvae transform into pupae and then emerge as adult mosquitoes, completing their life cycle during the short Arctic summer. This rapid growth reduces their exposure time to aquatic predators like diving beetles, contributing to higher survival rates to adulthood in warmer conditions.
Their Impact on Wildlife and Humans
The presence of large mosquito swarms in Greenland has a noticeable impact on both local wildlife and human visitors. For Arctic wildlife, particularly caribou, these swarms pose a significant challenge. Mosquitoes are aggressive feeders, swarming in large numbers to obtain blood meals from mammals. This relentless harassment can distract mother caribou from foraging, leading to reduced energy and milk production for their calves. In severe cases, particularly intense mosquito seasons have even been linked to the deaths of caribou calves.
For humans, Greenland mosquitoes are primarily a nuisance rather than a health threat, as they do not carry diseases common in warmer climates. However, their sheer numbers can be overwhelming, making outdoor activities uncomfortable. Visitors and residents often resort to protective measures such as head nets, insect repellent, and long clothing to minimize bites. Despite their annoyance, these mosquitoes do play an ecological role, serving as a food source for birds and other insects during the brief summer.
Understanding Their Swarms
The formation of the large swarms of Greenland mosquitoes is a result of several environmental and biological factors. The primary breeding grounds are the shallow wetlands created by snowmelt on the tundra. These temporary ponds are among the first areas to thaw in the spring, allowing for early mosquito development. The synchronous emergence of adults means that vast numbers appear at roughly the same time.
The short, intense Arctic summer condenses the mosquitoes’ activity into a brief, overwhelming period. Female mosquitoes require a blood meal to produce eggs, and with such a limited warm season, they are highly aggressive in their pursuit of hosts. Research indicates that warmer spring temperatures lead to earlier emergence and faster development, increasing the overall mosquito population. This means more mosquitoes survive to adulthood, particularly if their emergence coincides with the calving season of caribou, providing an abundant and less mobile food source.