Oahu honeybees imperiled
By Jan TenBruggencate
Advertiser Science Writer
By Jan TenBruggencate
Beekeepers and farmers across the state are fearful the tiny varroa mite, which is infesting bee hives in all parts of O'ahu, may kill off as many as nine out of 10 of wild hives on the island.
It has a potentially huge impact on some agricultural crops that depend on bees for pollination, and also will affect many backyard trees and gardens.
The state is launching an aggressive campaign to prevent the spread of the mites beyond O'ahu, and in particular to keep them off the Big Island, the heart of the state's bee industry.
Varroa mites are tiny sucking creatures that feed on the blood of bees. Bees can survive the low-population early invasion, but as the mites reproduce and more and more of them attack individual larvae, pupae and adult bees, the bees and hives are weakened. Some bees become deformed.
Because bees have been present on the Islands for so long, researchers aren't certain what agriculture would be like without them, said Carl Evensen, an extension specialist with the College of Tropical Agriculture and Human Resources.
"I think we can assume that this (mite infestation) could be serious, but I don't think we know how bad it will be," Evensen said.
On the Mainland, wild hives in infested areas have declined by 90 percent.
The mites were first identified here in April, but it appears they have been on the island unnoticed for months and perhaps years.
The potential negative effects begin with the honey business, whose statewide value is about $1.5 million annually. On top of that, beekeepers make millions of dollars selling healthy queen bees to the Mainland for use in starting new hives. That business is successful largely because Hawaiian beekeepers can guarantee they will deliver pest-free queens.
But the value of bees to crops outpaces the honey and queen business. State agriculture officials estimate the figure on O'ahu agriculture at between $10 million and $15 million; statewide it's close to $50 million.
Honeybees will celebrate their 150th anniversary in the Hawaiian Islands this year. After several failed attempts, successful hives arrived in 1857.
The mites' voracious appetite for bees also will affect other crops. Macadamia, lychee and rambutan trees, all of which depend heavily on bees for pollination, no longer will be producing bumper crops without bees, said Mike Nagao, horticulturist with the University of Hawai'i's College of Tropical Agriculture and Human Resources.
Some varieties of citrus — notably pomelo — are expected to be hurt as well, he said.
And many non-tree crops are affected. O'ahu has 600 acres planted in cucumbers and watermelons alone — which depend on bees as key pollinators. Their production likely will be way down without plentiful bees.
BIG ISLAND UNEASY
Big Island farmers and beekeepers are watching O'ahu's situation closely, and they are worried.
"If the mite gets here, we don't have organic honey anymore (since pesticides may be needed to control the mites). In terms of the queen operation, I don't know what we'd do," said Janice Horton, vice president of Hawaiian Queen, which markets queen bees to Mainland beekeepers.
"I think it goes way beyond the bees," said Ole Fulks, president of the Big Island Beekeepers Association. "It's a major threat to agriculture throughout Hawai'i. There won't be many feral (wild) hives, and the major crops are dependent on feral bees."
"It would be a disaster if that mite got over here. This is an agricultural island," said David Rietow, president of the Hawai'i Macadamia Nut Association. "In macadamia nuts, bees are a just-in-case pollinator.
"I think if the bees all died off, we'd still have a crop, but I don't know how much it would drop. We need all the bees we can get."
Nagao said that bees may be far more important to macadamia nuts than some farmers know. He said macadamia nut trees will set some fruit without bees, but they need cross-pollination with different varieties for a strong fruit set, and bees are the best way to get that.
Most of the state's coffee industry is self-pollinated, but bees help, said Roger Kaiwi-Machen, vice-president of the Hawai'i Coffee Association and operator of Captain Cook Coffee Co.
"If there's no bees here, it will slow down our pollination. We see thousands of bees on our flowers," Kaiwi-Machen said.
"Bees are the prime pollinator for our tomatoes, melons and cucumbers," said Richard Ha, of Hamakua Springs, a diversified agriculture company at Pepe'ekeo, Hawai'i.
There are techniques for causing tomatoes to pollinate themselves, but they are labor-intensive, he said. With other crops, he would be looking for varieties that don't need much fertilization, he said.
Skip Bittenbender, professor of tropical fruit and soil sciences at the College of Tropical Agriculture and Human Resources, said some crops — notably banana, cacao, papaya and pineapple — will be little affected. Macadamia, guava and mango will have a more significant impact, and some citrus, lychee and rambutan more still.
The state Department of Agriculture recognizes the threat and is taking it very seriously, said Neil Reimer, an entomologist and plant pest control branch chief at the department.
State officials propose the eradication of infested hives. They will use a $650,000 appropriation by the 2007 Legislature to pay beekeepers for their lost hives and to help cover the cost of establishing new ones with healthy queen bees.
Reimer said the state is also proposing bee quarantines around airports and harbors to limit the spread of the tiger-striped buzzers. That effort would involve tracking down and eradicating any feral hives near a transportation hub, to prevent stray infested bees from hitchhiking to another island.
"I believe, around ports of exit, a bee-free zone is very prudent," said entomologist and former beekeeper Steve Montgomery.
It's not known how the mites got to O'ahu — it is illegal to import bees to Hawai'i, and mites can't survive for more than a few days without a bee on which to feed. They were first spotted in early April on bees in Makiki hives.
"After we found it, we started conducting surveys across O'ahu, and we found it pretty much everywhere we looked: Waimanalo, Nanakuli, Wai'anae, Wahiawa, Mililani. It's in the commercial hives, but it's also widely distributed in feral hives," Reimer said.
The level of infestation is such that Reimer believes they have been on the Island at least a year, and perhaps longer.
The department quickly sent inspectors around the state — including to Kona, the heart of Hawai'i's honey industry — but found that only O'ahu seems to be infested with varroa mites so far.
"We sent a crew to Kona. The queen and honey producers — some guys have as many as 4,000 hives. That's where the really professional beekeepers are," he said.
Most of the state's other operators are comparatively small — many of them managing bees as a part-time business.
Reimer said the state plans to work closely with beekeepers to try to control the threat on O'ahu so the likelihood of spread is minimized. And beekeepers will be asked to inspect their hives regularly, to catch early any new movement to a Neighbor Island.
"Eradication on O'ahu is not possible. But we're going to hit the mites really hard," he said.
Montgomery agreed that it is probably impossible to wipe out varroa mites on O'ahu. He said New Zealand tried and failed to stop an invasion there.
"If they can't do it in New Zealand, there's not much hope Hawai'i can do it. New Zealand is the world leader in biosecurity," Montgomery said.
Howard McGinnis, one of O'ahu's few full-time beekeepers, said he owns 120 hives and assists farmers with about 80 more.
"I have seen the impact of the mite on hives out in Kapolei and 'Ewa. It's doing some pretty good damage," he said.
Severely impacted hives have fewer bees, less honey and are less able to keep their hives clean, he said.
There are mite-killing chemicals beekeepers can use to try to control the impact of the parasites, but McGinnis said he plans to try nonchemical means to try to keep mite populations down. But he said it will cost money and take more of a beekeeper's time to manage the infestation.
The only good news for beekeepers is a potential new source of revenue. If feral hives are depleted severely, beekeepers may be able to market their hives to farmers for pollination — delivering hives to the fields during flowering periods.
That's an active business in agricultural areas on the Mainland, but it has not been a significant part of Hawaiian beekeeping.
Reach Jan TenBruggencate at email@example.com.