HILO, Hawai'i — In just over a year's time, the varroa mite, a parasite that kills honeybees, has spread from the Hilo Bay area north to Onomea and south to Pahala, researchers say.

And it is not a matter of if, but when, the mites will spread to West Hawai'i, said Ethel Villalobos, an entomologist at the University of Hawai'i's College of Tropical Agriculture and Human Resources.

Although it isn't known how quickly it will happen, Villalobos said it will because bees are naturally on the move seeking sources of pollen, and farmers and beekeepers often move hives, and can unknowingly move a colony infested with parasites.

"The bottom line is: Varroa mites have been all over the world and the Mainland for the last 20 years, and it's substantially changed the way agriculture is done on the Mainland. It will substantially change the way we do agriculture here," said Richard Johnson, owner of Onomea Orchards and president of the Hawaii Tropical Fruit Growers.

"It's not the end of agriculture," he said. "It wasn't on the Mainland. We're going to have to learn to live with it; we're not going to eliminate the varroa mite. ... It's going to become an art of living with varroa."

More than 100 people attended the varroa mite panel discussion, part of the 19th annual Hawaii International Tropical Fruit Conference held Saturday at the Hilton Waikoloa Village. The panel featured researchers from UH's College of Tropical Agriculture and Human Resources varroa mite project.

Established on O'ahu and discovered near Hilo just over a year ago, the mite attaches to the European honeybee, burrows beneath its skin and feeds on the bee. Eventually, the mites spread in the bees' hives, living off their blood. Mites reproduce within single cells of bees and larvae.

The mites weaken the bees, allowing other viruses and diseases, such as deformed wing virus, to kill off the bees. Once a colony dies, bees from healthy colonies often take over the diseased hive, thus spreading the mites.

In Hilo, the prognosis appears to be grim for the 130 feral hives that have been documented, said Scott Nikaido, who provides research support for the project. Within a year, 90 percent of those feral hives could be gone, reducing the bees that pollinate local farmers' crops, he said.

Should the mite spread islandwide, researchers say that between 75 percent and 90 percent of feral hives will be lost. For managed hives, researchers expect that 50 percent of those will succumb to the varroa mite.