By Scott Martindale
COSTA MESA – State agricultural inspectors are canvassing a residential neighborhood near the Santa Ana River this week after finding a colony of an aggressive ant species in someone’s front yard, the first documented sighting of the pest in its natural environment in California.
The colony of big-headed ants was discovered in Costa Mesa’s Mesa Verde neighborhood earlier this month by an amateur entomologist, who collected a sample and sent it to Los Angeles County officials for identification, said Mike Bennett, Orange County’s agricultural commissioner.
On April 14, L.A. County agricultural officials confirmed the presence of the Pheidole megacephala species in the Costa Mesa home’s front yard, at Europa and Kornat drives, Bennett said.
“This is the first time we’ve seen it in California other than in a shipment of plants or flowers,” Bennett said. “It’s nothing to be alarmed about – we just want to check the spread of it so we can figure out what to do.”
Big-headed ants can bite humans, but their bite is painless and not harmful. Native to Africa, they travel in plants and via mailed packages to other parts of the world.
Bennett said a team of about 10 agricultural inspectors and UC Riverside scientists began going door to door this week asking Mesa Verde residents to inspect their front and back yards.
So far, the team has found only the one ant colony, Bennett said, although officials plan to survey other neighborhoods within a one-mile radius of the colony.
“It is an invasive species, and we have an obligation to try to prevent invasive species,” said Steve Lyle, a spokesman for the California Department of Food and Agriculture.
Even if state and county agricultural inspectors find more of the ants, it’s unclear what, if anything, will be done.
The species discovered last month isn’t the only variety of big-headed ant documented in California, Bennett said.
Authorities, though, are wary of these soil-nesting ants because they’re considered an agricultural pest and one of the world’s most invasive insects. Not only do they tend to invade homes in large numbers in search of food and water, but they also displace other ants and eat beneficial insects, officials say.
The neighborhood canvassing in Costa Mesa is expected to wrap up this week, and then authorities will decide whether to exterminate and/or continue monitoring the colony, Bennett said.
Residents who wish to report a possible sighting can call the California Department of Food and Agriculture’s hotline at 800-491-1899. However, Bennett said, big-headed ants look similar to other common varieties of ants, especially to an untrained eye.