Warming temperatures are causing Arctic mosquitoes to grow faster and emerge earlier, significantly boosting their population and threatening the caribou they feast on, a Dartmouth College study finds. The study predicts the mosquitoes' probability of surviving and emerging as adults will increase by more than 50 percent if Arctic temperatures rise 2 °C. The findings are important because changes in the timing and intensity of their emergence affect their role as swarming pests of people and wildlife, as pollinators of tundra plants and as food for other species, including Arctic and migratory birds.

The researchers say the climate-population model they developed for Arctic mosquitoes and their predators can be generalized to any ecosystem where survival depends on sensitivities to changing temperatures.

The study appears in the journal Proceedings of the Royal Society B: Biological Sciences. A PDF is available on request.

Climate change is raising temperatures globally, which greatly influences insect physiology, growth rates and survival, including their ability to elude predators. Average temperatures in the Arctic have increased at twice the global rate in the past 100 years, and the low biodiversity of Arctic ecosystems provided a simple predator-prey interaction for this study. Arctic mosquitoes develop in shallow temporary ponds of springtime snowmelt on the tundra, where their top predators are diving beetles.

Using field and lab studies, the researchers measured the impacts of increasing temperatures on development and death rates from predation on immature mosquitoes in western Greenland. They then developed a model to evaluate how temperature affects their survival from the immature stage to adult biting stage across a range of temperatures in future climate change scenarios for the Arctic.