Conservation and Biodiversity

Buzz off: How invasive mosquitoes are irritating the US

Mosquitoes are spreading, which doesn’t bode well for our skin or health. One of the most migratory and invasive species is the Asian tiger mosquito, or Aedes albopictus. On top of causing those irritating itches, tiger mosquitoes can carry and transmit many diseases, such as dengue fever, yellow fever, West Nile virus, chikungunya and Zika. Under lab conditions, these mosquitoes can transmit up to 20 viruses.

Initially migrating to the U.S. in the ‘80s, the tiger mosquito has spread across the country, becoming a nuisance, as well as a public health problem. Unlike other mosquitoes, the tiger mosquito — recognizable by its black body and single white stripe — is active all day long, making it especially difficult to avoid.

Recent scientific modeling points to climate change as a key culprit of this spread: A warming planet with more frequent rainfall is a perfect habitat for mosquitoes, which thrive in warm, humid environments. A warming Earth also creates different habitats for species, driving species to either adapt or move.

As people continue to release dangerous greenhouse gases like CO2 into the atmosphere, mosquitoes migrate across regions, even continents. The higher the increase in warming, one study suggests, the greater the distances traveled by species. That’s how a mosquito from Asia can end up on the doorstep of North America. And with rising temperatures, increased humidity and longer summers, these mosquitoes are happy to stay — and multiply.

Climate change allows invasive pests like the tiger mosquito to live and reproduce in areas it usually never touches. One study focusing on the northeastern United States predicts that “the land area with environmental conditions suitable for [tiger mosquito] populations is expected to increase from the current 5% to 16% in the next two decades and to 43%–49% by the end of the century.”

Urbanization increases the threat, because tiger mosquitoes breed primarily in cities. By 2050, 70% of the world’s population will live in urban areas, according to the U.N. As more people move to cities, more people are susceptible to these insects and the vector-borne diseases they carry.

So, what can we do to stop the spread? Mosquitoes flock to stagnant water, so limiting these sites is a good first step. Even something as small as a water-filled bottle cap is big enough for a mosquito to lay its eggs. You can also dress for defense: Wear long sleeves and pants, socks and shoes, if you’re going to be outside for a while.

Globally, however, it comes down to one thing: We need to cut down our greenhouse gas emissions to limit the spread of the warm, wet climates that mosquitoes love. Climate change and biodiversity are incredibly complex systems that rely on delicate balances of nature. When CO2 floods the atmosphere, rapidly altering the Earth’s climate, the balance is thrown off, and mosquitoes multiply. Warmer temperatures and extreme weather events make even more suitable habitats for mosquitoes — and infectious diseases — around the globe.

The bottom line is, as mosquito habitats increase, so does our risk of disease. Our increased use of greenhouse gases only encourages this. So forgo the car, eat more plant-based meals and tell your politicians to take bold action to curb climate change. Your mosquito-bitten ankles will thank you.