HOMESTEAD, Fla. — Florida’s avocado industry remains on alert for a tree-killing disease that’s moving closer to south Florida production areas.

In late February, the Florida Department of Agriculture and Consumer Services discovered laurel wilt disease, a fungus that destroys red bay and avocado trees, on three swamp bay trees in south Miami-Dade County, about 7.5 miles north of the state’s commercial avocado production region near Homestead and Florida City.

Since then, inspectors have trapped several redbay ambrosia beetles, which spread the disease.

“It’s scary,” said Manny Hevia Jr., secretary-treasurer of M&M Farm Inc., Miami. “It’s a scary little bug. I have seen trees afflicted with it. It flat out kills the tree.”

Growers remain worried and are supporting as much research as they can to stop the bug’s spread, Hevia said. He added that many south Florida jobs rely on the region’s avocado business and many groves help provide retirement incomes.

Aerial surveys in the densely treed area bordering the Everglades west of Kendall, Fla., on the south side of Miami, showed 105 suspected infested trees, and 38 tested positive for the disease.

“The beetle is right here at our doorstep,” said Bill Brindle, vice president of sales management for Brooks Tropicals Inc. “But to the best of my knowledge, there has not been an avocado tree found in Miami-Dade County yet that has been affected by it, so that’s positive.”

Researchers are collecting, identifying and cataloging parasite insects found in the trees and have many research projects underway to study ways to limit the spread of the beetle and the disease, said Denise Feiber, the state agricultural agency’s public information director.

Trapping has been intensive since February 2010, when the agency increased its surveillance in the Miami-Dade County area after the first redbay ambrosia beetle was trapped in a residential area, 12 miles north of the commercial production area, Feiber said.

“You can see how it’s (the insect) moving to the south,” she said. “What we are finding is it appears the avocado tree is not the preferred host of beetle. It prefers the swamp bay trees. That’s good news.”

Entomologists are studying the beetles’ life cycles, and pathologists are probing how the beetle fares during wood chipping of red bay trees, Feiber said. It appears the beetles don’t survive the chipping process, she said.

Peter Schnebly, co-owner and chief executive officer of Fresh King Inc., echoed industry worries.

“It’s hard not to think about it when we haven’t seen any solutions to the issue,” he said. “We are more anxious and are running out of time. The beetle is within a stone’s throw of us. I feel confident they (researchers) will come up with ways to control it, but the issue is will they be able to do that quick enough at this point? It could take a year to come up with a solution but it could hit before that.”

Eddie Caram, general manager of New Limeco LLC, Princeton, doesn’t think the industry is terrified, he said.

“There’s still concern, of course, but the mood is a little better,” he said. “Everyone is concerned. We just try to keep up with it to see what they’re finding and what they are doing.”

The majority of Florida avocados are grown in groves south of Kendall Drive, in the southern half of Miami-Dade Co., just south of Miami.