A swank town in California’s central coast where celebrities from Oprah Winfrey to Prince Harry have bought properties, has become a hot spot for another reason: an active infestation of red imported fire ants.

The Santa Barbara county agricultural commissioner’s office is addressing an active infestation of these ants in Montecito, California, according to a statement issued last week.

This infestation likely originated from ant-infested nursery stock shipped from Riverside county in September 2023, according to officials.

“This is the only known infestation in the county,” according to the statement.

Staff from the commissioner’s office, along with the California department of food and agriculture, the University of California Cooperative Extension, and Riverside county agricultural commissioner’s office, are conducting regular property surveys.

Red imported fire ants, native to South America, have established themselves in parts of southern California, particularly in Los Angeles, Orange, and Riverside counties, according to researchers at the University of California, Riverside.

The first recorded sighting in California was in 1984. Since then, there have been periodic outbreaks in several counties.

Stings from these ants are painful and can cause pustules that may scar if infected, and a small percentage of the human population is allergic to these stings. Newborn livestock and poultry are also vulnerable to attacks.

These ants can clog irrigation lines, short-circuit electrical systems and displace native wildlife, including young birds and lizards. Their stinging behavior is also hazardous to fieldworkers and poses a significant risk to agriculture by feeding on various hosts, particularly turf.

The ants, mainly originating from Argentina and Brazil, pose a significant threat to California’s agricultural economy because they require quarantine of nursery products to prevent spreading through potting soil. In Texas, for example, over $1.1bn is spent each year on pesticides for fire ant control and $872m of those funds is used to control the ants from infesting lawns in urban areas.

No fire ants-related quarantines were in place in Santa Barbara amid the infestation.

Nursery products ranked second in value in the county’s agricultural economy, below strawberries, in the 2023 Santa Barbara County Crop and Livestock Report at $122,301,000.

Residents were encouraged to contact the Santa Barbara county agricultural commissioner’s office if they detected these ants or bring a sample to their offices.

“There are native fire ants and Argentine ants that are not hazardous and the quickest way to distinguish RIFA from other ants are their aggressive behavior, not color or size,” the county of Santa Barbara said in a Facebook post.

Montecito, located about 80 miles west of Los Angeles, is known for its celebrity and affluent community. Current and former residents include Ariana Grande, Adam Levine, Rob Lowe and others.