CLEARFIELD — Invasive Mosquito Species Found in Northern Utah

An invasive species that made its way to southern Utah almost ten years ago has now reached northern Utah.

Davis County Health Department officials announced on Monday that an Aedes aegypti mosquito, known as the “yellow fever mosquito,” was identified at Bicentennial Park in Clearfield during routine mosquito monitoring on October 8. This is the first recorded instance of this species in Davis County.

Natively from Egypt, this mosquito is recognized as a carrier for several viruses, including Zika, dengue, and the yellow fever virus, according to the European Centre for Disease Prevention and Control.

The Centers for Disease Control and Prevention have indicated that while the presence of this mosquito does not inherently increase disease spread risk, it is known to transmit viruses more efficiently than other invasive mosquito species present in the U.S.

“Due to Ae. aegypti mosquitoes’ tendency to live and feed close to humans, the likelihood of them spreading viruses is higher compared to other mosquito types,” the agency noted in 2024.

This species is also distinct for its daytime biting behavior, often targeting ankles, as mentioned by Davis County Health officials on Monday. They prefer to lay eggs in small amounts of stagnant water, which could be found in various places such as buckets, unused containers, or even valve boxes.

These mosquitoes typically don’t travel far and are drawn to warmer climates. While the exact origin of this species in Davis County remains uncertain, they have been regularly detected in southern Utah since 2019.

In response to the finding, additional traps were deployed, and neighborhood inspections began, shared Greg White, the manager of the Mosquito Abatement District-Davis.

“So far, we haven’t identified any more invasive Aedes aegypti mosquitoes. We will continue our extra trapping and treatments until temperatures drop,” he commented, believing that tackling the species when its population is still low will be more effective.

Davis County health officials are urging residents to:

• Apply mosquito repellent containing DEET or another EPA-registered product.
• Wear loose-fitting, light-colored long sleeves and pants to reduce bites.
• Eliminate any standing water in their yards, regardless of its size.
• Keep gutters clear of debris.
• Ensure that doors and window screens are in good condition to prevent mosquitoes from entering their homes.
• Regularly trim weeds and tall grass.

Residents who notice small, dark mosquitoes biting during the day are encouraged to report these sightings to the Mosquito Abatement District-Davis by calling 801-544-3736.

“Right now, these diseases are mainly linked to travel,” stated Brian Hatch, director of the Davis County Health Department. “The presence of this mosquito in our area increases the chance that these illnesses could be transmitted locally, a trend that is already becoming apparent in various regions across the United States.”