If you’ve been stalked by tiny striped mosquitoes this summer, you’re not alone. These bold black-and-white bugs, aka Aedes aegypti, are “aggressive biters” and “a little bit sneakier” than other mosquitoes, said Nick Pederson, Urban Biology Division manager with Albuquerque’s Environmental Health Department.
Found in Albuquerque and points south, the Aedes aegypti mosquito has spread rapidly across the state in recent years as a result of climate change.
They may be just a nuisance now, but these mosquitoes are the primary route of transmission of four critical mosquito-borne viruses: Zika, Chikungunya, dengue fever and yellow fever. None of these diseases have been transmitted in New Mexico, Pederson said, but the Aedes aegypti’s uniquely effective adaptations to its hosts – humans – means it poses a particular danger.
Aedes aegypti “can cause truly explosive epidemics,” said Kathryn Hanley, a regents professor of biology at New Mexico State University with expertise in emerging mosquito-borne viruses.
These mosquitoes are “human-focused,” Hanley said: They’re not interested in biting other animals. Unlike the West Nile virus, transmitted from birds to humans, humans are the reservoir for these four viruses. So one Aedes aegypti mosquito can spread a virus rapidly from person to person.
Aedes aegypti die if exposed to cold temperatures. But climate change brings milder winters that makes it easier for them to overwinter, Hanley said.
The United Nations Intergovernmental Panel on Climate Change report published this year warns “climate change is projected to impact the distribution, abundance and infection rates of mosquitoes in North America.” The report projects an increasing risk of mosquito-borne diseases, including dengue, endemic in Mexico, which is predicted to spread north across the border.
In 2017, after the Zika outbreak in Latin America, the Centers for Disease Control and Prevention modeled Aedes aegypti’s potential spread across the U.S. At the time, the species’ arrival in Albuquerque was labeled “unlikely.” But, Pederson said, “We now have Aedes egypti well established in Albuquerque, and it does not appear to be going anywhere.”
Native to Africa, the species arrived in the Americas during colonial times and became established in the southern U.S. They were discovered in Doña Ana County in 2016, and first documented in Albuquerque in 2018.
Pederson has observed the local impacts of climate change in Albuquerque. Mosquito season used to start around Memorial Day and wrap up by Balloon Fiesta, he said, but now “we’ve seen an extension of the mosquito season by often weeks on either side of that time frame.” In 2021, he observed mosquitoes into November.
Aedes aegypti’s lifestyle is another key factor in their growing range. They live inside or in proximity to homes, where they’re insulated from cold weather.
That makes it hard to control their populations, Hanley said. Standard methods like spraying for adult mosquitoes may not be a viable option within or close to homes.
Since these mosquitoes need to live near humans, they’re only found in areas with dense human populations, not in farmlands or wetlands, Hanley said. She predicts they will continue to move north through New Mexico, leapfrogging between cities. But high-elevation cities like Santa Fe with cold winters may be inhospitable to them – for now.
Pederson emphasizes there’s no quick fix for Aedes aegypti. “It’s not something that the city or county is going to come in and spray away,” he said. Every neighborhood needs to have management plans to help lessen their numbers.
Aedes aegypti make a big impact in urban areas in part because they’re more widespread than other mosquitoes. Pederson surveys numerous sites throughout Albuquerque and Bernalillo County, and has found Aedes aegypti everywhere West of the Sandias. Unlike other mosquito species that need bigger areas of standing water, Aedes aegypti breed in small containers, like rainwater collected in a children’s toy or a dish under a potted plant.
“These mosquitoes do quite well in just a typical city of Albuquerque backyard,” Pederson said. In the last two years, he’s received many calls from longtime residents complaining they’ve never had mosquitoes at their homes until now.
Pederson has several tips for minimizing these pests. Dumping out containers of water helps, but Pederson said scrubbing them is best, since their eggs can withstand drying and hatch after getting soaked again. And rain barrels should be screened from mosquitoes.
Pederson noted Aedes aegypti are active during the daytime, mostly a couple hours after dawn and a couple hours before dusk. Wearing repellent when outside will deter them. He recommends a DEET-based repellent or one with lemon-eucalyptus oil.
Yet while efforts in homes and neighborhoods are important, the big picture for mosquito control across the state is critical.
Hanley said New Mexico isn’t prepared to address a new mosquito-borne disease. “My concern is predominantly that we don’t have uniform surveillance for mosquitoes and mosquito-borne diseases in the state.” She cited Albuquerque’s program as an example of good surveillance. But she called the rest of the state’s surveillance “spotty” and said mosquito control programs at the county or district level are “very fragmented.”
The New Mexico Department of Health did not provide a representative for an interview for this article. In a written statement, spokesperson David Morgan said, “The Department of Health recognizes insect population surveillance to be among the many funding opportunities important in our ongoing effort to rebuild public health infrastructure.” Morgan also noted the department’s vacancy for a state entomologist.
Hanley said the problem isn’t lack of expertise across the state. It’s lack of funding. She calls for an increased budget via a legislative line item. Without adequate resources dedicated to mosquito-borne viruses, she said, “we will mostly be blind to what’s happening in the state.”
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