RAYMONDVILLE – The spread of the Mexican Fruit Fly is still under a microscope while the citrus industry remains on edge.

One pregnant fly was caught in Willacy County, an area that will stay under quarantine for half a year.

The tiny pest continues to be a scare for farmers across the Rio Grande Valley. Other than being a nuisance, they are harmless to people. But to citrus fruit, the Mexican Fruit Fly is deadly.

Mission resident Dale Brockman says the battle against the fly had him laboring over the holiday weekend.

“It’s pretty devastating to the crop. I wasn’t aware how a little bitty fruit fly could be so devastating and destroy a whole crop,” he says.

The tiny flies, most commonly seen buzzing around the fruit at home, are the offspring. Fully grown ones have a yellow tint and are about a third the size of a finger.

The fertile female population in the RGV has doubled in just a month, say experts.

“We have 16 positive fruit flies in the Hidalgo County area, which potentially means that we could start a quarantine area in the northern Hidalgo County or Mercedes area,” says Lorenzo Garza, outreach specialist for residences for Texas Citrus Pest and Disease Management Corporation.

The fruit is the catalyst to the species’ survival.

“Fertile fruit flies normally mate inside the fruit itself. They inject its larvae, and it reproduces,” explains Garza.

Valley residents are busy pulling the citrus from the trees to prevent the spread of these pests.

“We have to make sure the fruit is kept picked,” says Brockman.

Garza says now that the citrus season is over, he along with employees with the U.S. Department of Agriculture are still urging people to pick.

Supervisory Plant Protection Quarantine Officer for the USDA Joseph Ramirez lists the rest of the methods they are using to stop the spread.

“We're using sterile insects that we're releasing. We also have additional traps at all the fly finds in the Rio Grande Valley, and we're also doing spray treatments where we find flies,” he says. “In addition to that, we do preventative sprays where we found flies the year before. We go back and we spray again on a monthly basis to try to mitigate that danger."

He says if growers do not plan to keep citrus after picking it, they should give it away or throw it away.

He adds there is a proper way to do that. Just cut the citrus in half so the fly larvae are released. Then, bag the fruit and toss it out.

The USDA says although the Mexican Fruit Fly is native to Mexico, the wind pushes the pests our way.

Ramirez says the agency’s teams have over 2,000 traps set around the Rio Grande Valley area that are checked once a week.

He says the section quarantined in Willacy County should be lifted in six months.