28-05-2025
Mosquitoes are adapting to warmer environments, risking spread of disease
Mosquitoes are adapting to warmer environments, risking spread of disease
This story has been updated to correct the misspelled name of Lisa Couper.
Warmer weather is lengthening the mosquito season in the United States, increasing populations of the pests and their ability to transmit diseases like Dengue fever and West Nile virus across the country.
Some mosquito species are more adaptable to heat and better suited for dealing with heat waves than other insects. That's according to a recent study by the University of California, Berkeley School of Public Health's Environmental Health Sciences Division, published in the Proceedings of the National Academy of Sciences.
'The most common prediction of how global change will affect mosquitoes and mosquito-borne disease is that populations will shift to higher altitudes and higher latitudes,' said lead author Lisa Couper in an interview with Berkeley Public Health in February.
'That is assuming mosquitoes won't adapt to heat. But mosquitoes have all sorts of adaptive capabilities,' Couper said.
Mosquito-borne illnesses continue to be a threat to millions in the United States.
Mosquitoes may be coming to you
As temperatures rise in numerous parts of the world, researchers have been fairly convinced that mosquitoes seeking warmer conditions will settle in previously uninhabitable areas.
A study published in 2019 in PLOS Neglected Tropical Diseases showed possible migratory routes of disease-spreading mosquitoes shifting north if climate change continues.
Maps from the study were based on estimates of future temperatures around the world.
Unable to view our graphics? Click here to see them.
Mosquitoes that spread diseases in the U.S.
Most mosquitoes don't carry disease. Those that do are called vectors.
Vectors means the insects spread diseases such as West Nile virus, encephalitis, malaria, dengue fever and chikungunya in humans, or heartworm parasites in dogs.
The main mosquito species that can carry diseases in the United States are:
More: Feds recommend pausing vaccine for mosquito-borne disease chikungunya in people over 60
Hotspots for mosquito populations this year
Mosquitoes affect some American cities more than others.
Orkin released its 2025 Top 50 Mosquito Cities List that places Los Angeles at the top for the fourth consecutive year. Other cities, including Detroit, Cleveland and Denver, made significant gains into the top 10.
Ways to protect yourself from mosquito bites
If you expect to be in an area where mosquitoes are, such as a park, lake or campsite, be extra careful when venturing outside. Mosquitoes are most active in the warmer months of March through October.
The Centers for Disease Control and Prevention says the best way to reduce the risk of infection is to prevent mosquito bites:
◾Use insect repellent, which includes DEET or picaridin.
◾Wear long-sleeved shirts and pants.
◾Treat clothing and gear with the insecticide Permethrin.
◾Avoid going outside at dawn and dusk, that's their most active time of day.
◾Take steps to control mosquitoes indoors and outdoors.
CONTRIBUTING George Petras, Mike Snider and David Robinson/USA TODAY NETWORK
SOURCE Centers for Disease Control and Prevention, UC, Berkeley School of Public Health's Environmental Health Sciences Division, Global expansion and redistribution of Aedes-borne virus transmission risk with climate change study, European Centre for Medium-Range Weather Forecasts, National Public Radio (NPR), Orkin and USA TODAY research
