Deadly Parasite
Worldwide plague reaches Hawai'i

by Alan D. McNarie

This plague is a pinhead-sized, crab-shaped mite, Varroa jacobsoni, that parasitizes honeybees. First discovered in 1904 in Java, it made its way to Singapore by 1951 and from there to the Asian mainland, Europe and North America. It leaped to other species, including the European honeybee, which had no natural defenses.
"The varroa has seriously damaged beekeeping in Russia, all of Europe and across the United States," says Gus Rouse of Kona Queen Hawai'i, one of a half-dozen local beekeeping operations. He says that beekeeping is still possible in infected areas but requires "many preventive measures."
Hawai'i was one of the last places on earth free of the deadly little pest and enjoyed a booming market for its honey and, more importantly, its mite-free queens, which were exported to the mainland to help restart hives in stricken areas. But last month, mite infestations were found in five locations on O'ahu. Those infected hives including four feral bee colonies: particularly bad news, since mites can be chemically controlled in commercial hives but usually wipe out wild colonies.
Crops threatened
The state's $6-7-million bee industry is at stake, as are crops that rely on bees for pollination: macadamias, pumpkins, melons, zucchini, guava, starfruit, cherimoya, custard apple, lychee, citrus and others.
The only non-native crops that don't require it are sugar cane and pineapple, says Michael Kliks, the president of the Hawai'i Beekeepers' Association.
Most of those crops are pollinated by wild honeybees, which are so common that Hawai'i's commercial orchards and farms have largely been able to operate without paying pollination fees to commercial beekeepers.
"[Growers] didn't care if they killed [bees]. There would always be more," says Kliks. But if Varroa mites get established, "wild hives will probably be wiped out."
Another casualty may be the islands' thriving organic honey industry. But there is an organic agent to combat the problem. In 2002 an EPA-funded study found that dusting bees with powdered sugar dislodged most of the mites.
Deadly adaptation
But once an infestation gets started, eradication is extremely difficult. Varroa mites are nearly perfectly adapted parasites. Their flat bodies lodge themselves in crannies in the bees' exoskeleton. They hang on in flight and are spread from hive to hive by the social insects.
The problem has been aggravated by monocropping and globalization. Most beekeepers worldwide rely on a single species of bee, the European honeybee, which has displaced many native pollinators around the world. And the shipping of bees around the world has made it easy for a single parasite to spread.
Native impact
Some native species in Hawai'i may actually benefit from bee mites. Honeybees are not a part of the native ecology. The bees compete with apapane for lehua nectar and pollen and with the amakihi for the nectar and pollen of upland mamane trees. They probably also compete with yellow-faced bees, the island's only native species.
"It's all just really kind of a black box. It's surprising how little is known about Hawaiian pollinators," says Rouse.
As of press time, the Hawai'i Department of Agriculture had stepped up inspections of beehives statewide and was at work on an "interim" quarantine rule that would forbid the interisland transport of honeybees, to help slow the spread of the disease. Rouse and other beekeepers who export queens to the mainland would not be affected, since they're sending clean bees to an area that's already infested. The state already bans the importation of bees from elsewhere.

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