State inspectors have found four varroa mites on bees that were trapped in Hilo Harbor — the first time the bee-killing insects have been found outside O'ahu.

These bee parasites pose a potential problem for farmers and beekeepers who depend upon the bees to pollinate crops, make honey and raise queen bees for export.

The varroa mite is one of the most serious honey bee pests. It is found across much of the world and has led to a decline of bee colonies worldwide.

"We were the last safe place in the United States," said Michael Kliks, Hawai'i Beekeepers Association president. "I'm not just frustrated. I'm angry as hell."

Four mites were found Wednesday in a swarm trap that had been deployed near Hilo Harbor. The mites were collected and frozen and tested yesterday to see if they were varroa mites.

In response, the state Department of Agriculture will send out teams today from its Plant Quarantine Branch to immediately destroy all feral bee hives within a five-mile radius of the harbor, where the varroa mites were found on bees near the Hilo Seaside Hotel, said Lyle Wong, state Department of Agriculture administrator for the plant industry division.

"We've been free of the mite until last year when it was found in Makiki," Wong said. "The plan was to contain the mite on O'ahu and not let it spread statewide."

The varroa mite was found on O'ahu in 2007 and since then, the state has been monitoring swarm traps around ports as an early detection method.

The state will be setting up additional traps and sampling for the mites in Hilo. A meeting with Big Island beekeepers has been set to provide them with sticky traps containing miticides to kill any varroa mites.

The mites weaken adult bees and cause baby bees to be deformed. They spread from hive to hive through bee contact.

On O'ahu, the state has been destroying bees around Honolulu International Airport and Honolulu Harbor to reduce hitchhikers, Wong said.

The Big Island is a large exporter of queen bees, which are vital to creating new colonies.

The bee-killing mite could cost farmers $42 million to $62 million a year if it wipes out the state's bee population, according to preliminary estimates by the state.

On O'ahu, crop losses are estimated to range from $10 million to $15 million a year, under the department's worst-case scenario. That poses a big hit for the state's $500 million a year agriculture industry.

"Queen bees are the basis of colonies," Wong said. "They lay eggs and make new hives for pollination and honey making. It's an important industry on the Big Island and important for agriculture statewide."