WAILUKU » Coffee growers on Maui are bracing for a destructive beetle to eventually make its way to the island.

The coffee berry borer has been wreaking havoc on Hawaii island for years. The pest made its way to Oahu in December.

"I’ve been a farmer forever, and I know the reality of these kinds of things, so I expect that at some point it will show up here," said MauiGrown Coffee President Kimo Falconer. "But we’re ready."

Preventive measures include some farmers restricting access to their orchards, the Maui News reported Tuesday.

"We’ve had to put signs up trying to reduce the amount of people walking through our fields, but really they can just walk right up there, and maybe they were in Kona yesterday doing a farm tour and there’s dirt on their shoes," Falconer said.

Falconer said his farm checks traps regularly and has trimmed back trees that are close to roads.

Some farms that used to offer educational tours no longer do so, said Sydney Smith, president of the Maui Coffee Association and owner of Maliko Estate Coffee. "The beetle is so tiny it gets spread by people coming from the Big Island from dirt on their shoes or their clothes," Smith said.

The beetle bores into the coffee cherry, and its larvae feed on the coffee bean, reducing yield and quality. Farmers might not discover them until after harvest.

It’s unknown how the beetle, native to Central Africa, arrived in Hawaii.

"We’re the last coffee-growing region on Earth to finally get it," Falconer said.

The state Department of Agriculture issued a quarantine order that requires a permit to transport unroasted coffee beans, coffee plants and plant parts, used coffee bags and coffee harvesting equipment from Hawaii island to other islands that are not infested with the coffee berry borer.

The coffee berry borer can cause yield losses of 30 to 35 percent with 100 percent of berries infested at harvest time, according to the University of Hawaii College of Tropical Agriculture and Human Resources.

A researcher is studying the effectiveness of the fungus spray used on Hawaii island and its affect on the pest’s distribution across farms, said Mark Wright, plant and environmental chairman of the college.

Kauai has also managed to avoid the beetle. Kauai Agricultural Research Center entomologist Russell Messing teaches farmers how to take samples and test for the beetle using a procedure and sampling kit he developed.