Recent research from North Carolina State University, published in Parasites & Vectors and Royal Society Open Science, suggests that localized mosquito-control practices may create conditions that favor the evolution of insecticide resistance in mosquito populations.
Aedes albopictus, commonly known as the tiger mosquito, is an invasive species that has become widespread across much of the eastern United States. It breeds in a variety of artificial and natural containers that collect standing water, such as gutters and buckets.
In North Carolina, control of this mosquito is often managed at the household level, either through private mosquito-control services or by individuals applying pyrethroid insecticides. These chemicals are widely used because they are effective against adult mosquitoes and considered among the safer insecticides for use around people, pets, and homes, but they are typically applied without coordination among neighboring properties.
Modeling Mosquito Mutations
In one study, a team led by Jennifer Baltzegar tracked the emergence and spread of a resistance mutation known as F1534S in tiger mosquitoes in Wake County between 2016 and 2024. They looked at the F1534S mutation, which researchers have associated with knockdown resistance.
The mutation was absent from the Wake County samples collected in 2016 and 2017. In 2023, the researchers detected the resistance-associated mutation in 84% of the sampled residential areas, and they found it in 39% of the mosquitoes they sampled. The researchers’ models indicated that the resistance allele was under strong selection pressure, meaning mosquitoes carrying it had a significant evolutionary advantage in the local environment.
“Homeowners with money will pay to spray for mosquitoes, which selects for localized resistance,” said Martha Burford Reiskind, associate professor of biological sciences at NC State and corresponding author on both papers. “Over time, as more and more resistance builds up in the population, it will become harder to control populations. The insecticides will no longer be as effective.”
Wealth as a Selection Pressure
A second study, led by Cole Butler, looked at how resistance is distributed across neighborhoods with different property values. The team sampled mosquito populations across 31 residential blocks throughout Raleigh, covering a range of property values. They found that neighborhoods with higher total property values, which the researchers used as an indicator of likely spending on pest control, showed higher frequencies of resistance. While the study did not track individual spraying habits, the pattern suggests that greater private investment in mosquito control may be contributing to the spread of resistance.
That pattern breaks from how insecticide resistance usually spreads globally. “We see the rapid rise of pesticide resistance in places like South America and Asia where there is continuous spraying in some countries,” Burford Reiskind said. “But resistance driven by private mosquito control is novel in the contiguous U.S., to our knowledge.”
How the Mutation Actually Works
The F1534S mutation occurs in the mosquito’s gene for the voltage-gated sodium channel, which is the same site where pyrethroid insecticides act. This genetic alteration decreases the mosquito’s sensitivity to pyrethroids and thus enables some individuals to survive exposure to insecticides. The resistance allele is only partially recessive, so not all mosquitoes display the full effect. As a result, the mutation can spread through a population before resistance is noticeable.
“This mutation is often the first to show up when there’s insecticide resistance,” Burford Reiskind said.
Where the Research Goes Next
Beyond being a nuisance, tiger mosquitoes can transmit diseases such as dengue, Zika, chikungunya, and dog heartworm. While the current studies did not assess disease transmission directly, Michael Reiskind, a professor at NC State and co-author of both papers, notes that future research will expand to include a broader range of neighborhoods. “We want to make a better effort to get a diversity of neighborhoods, age, and wealth to extend our findings and see whether they work at different housing densities and wealth levels,” Reiskind said.
The researchers recommend using integrated pest management techniques since these methods decrease the need for chemical insecticides. They stressed that eliminating standing water where larvae develop is a key preventive measure. Effective pest control means addressing the entire life cycle and not depending just on chemical insecticides.
Putting these integrated approaches into practice may be challenging since many suburban homeowners already rely on seasonal mosquito-spraying services. The rapid development of resistance in Wake County suggests that managing this trend will likely require cooperation among homeowners, pest control companies, and public health agencies. Achieving that cooperation may require these groups to rethink how they manage private mosquito control.
Austin Burgess is a writer and researcher with a background in sales, marketing, and data analytics. He holds an MBA, a Bachelor of Science in Business Administration, and a data analytics certification. His work focuses on breaking scientific developments, with an emphasis on emerging biology, cognitive neuroscience, and archaeological discoveries.