Warmer climate will give more Arctic mosquitoes

Mosquitoes, as well as swarms of gnats like the one in the photo, can be a big annoyance during the short Arctic summer.

As temperatures warm in the Arctic, mosquitoes are able to emerge earlier, grow faster and survive longer – and in higher numbers, according to a new study. 

Large blood-sucking mosquitoes are already the bane of many people, reindeer and other mammals living in the north. But as temperatures warm, mosquitoes above the Arctic Circle will emerge earlier from their ponds, they will grow faster and live longer, according to a study by researchers at Dartmouth College’s Institute of Arctic Studies.

According to the study, the survival rates for mosquitoes will increase by 53 percent with a 2 degrees Celsius temperature rise in the region.

Arctic mosquito eggs develop and hatch in shallow, temporary ponds of springtime snowmelt. The research reveals that warming temperatures cause the mosquitoes to hatch earlier and shortens their development time through the larval and pupal stages by about 10 percent – when they are vulnerable to aquatic predators such as diving beetles. This increases their chances of surviving until adulthood.

Rising mosquito numbers will likely have serious consequences for caribou and reindeer herds, which are one of the main food resources for many Arctic communities, the researchers warn.

Arctic mosquitoes’ reproductive success depends on the females finding a blood meal, which is expected to increase because warming more closely synchronizes their life cycle with reindeer calving. The calving season benefits mosquitoes by giving them a larger, less mobile herd to feed on, including vulnerable calves.

“Increased mosquito abundance, in addition to northward range expansions of additional pest species, will have negative consequences for the health and reproduction of caribou,” says lead author Lauren Culler. “Warming in the Arctic can thus challenge the sustainability of wild caribou and managed reindeer in Fennoscandia (Norway, Sweden, Finland and parts of northwest Russia), which are an important subsistence resource for local communities.”