Insect traps near the Santa Clara County Fairgrounds last month have caught Oriental Fruit Fly (OFF) – the pest that is commonly found across southern Asia mainland.

“We found one, and then we found two, and we found three,” Joe Deviney, Santa Clara County’s Agricultural Commissioner, shared to ABC7 News.

A quarantine was imposed by the California Department of Food and Agriculture (CDFA) in about 96-square-miles as Deviney said six flies could usually be a sign of “breeding population”.

“But that’s just to ensure that we’re focusing on the potential hosts in that area,” the commissioner said. “The businesses that might have those hosts, the farmers markets, the roadside vendors. We’ll be making sure that they’re all under compliance and not doing anything that would spread it to another county or further and further out.”

Included in the quarantine zone are the fairgrounds, south to Santa Teresa County Park and north to the Alum Rock neighborhood, as shown in the CDFA map.

Sharing of backyard fruit between residents in the quarantine zone is not allowed to prevent the spreading of pests.

“That would make farmers have a more difficult time growing the food, they’d probably have to do more pesticides- which no one wants to do,” Deviney shared. “It would be more difficult for them to export things, because other countries don’t want this, these flies.”

Fruit attached to trees, instead of the rotten and detached ones, are being attacked by the flies, Deviney said.

“It likes to lay its eggs in those hosts. Those eggs turn into larva, maggots- and they ruin the fruit,” he explained. “And they actually infest the fruit on the tree. We have some fruit flies that are native that after the fruit falls and starts to rot, then they come in.”

OFF could find its way into the Bay Area as the place has no real winter – which tropical flies hate.

Treatment against the pests started last week, he said, and more action is still needed, ABC7 reported.

“It’s called ‘male attractant treatment.’ So we splat a little bit of a food attractant, mixed with a little organic pesticide on street trees, just about 10-feet up or eight feet out of the reach of anybody,” he said, saying that the fruit flies die when they take in the mixture.