A parasitic mite has helped a virus wipe out billions of honeybees throughout the globe, say scientists.
A team studying honeybees in Hawaii found that the Varroa mite helped spread a particularly nasty strain of a disease called deformed wing virus.
The mites act as tiny incubators of one deadly form of the disease, and inject it directly into the bees’ blood.
This has led to “one of the most widely-distributed and contagious insect viruses on the planet”.
The findings are reported in the journal Science.
The team, led by Dr Stephen Martin from the University of Sheffield, studied the honeybees in Hawaii, where Varroa was accidentally brought from California just five years ago.
Crucially some Hawaiian islands have honeybee colonies that are still Varroa-free.
This provided the team with a unique natural laboratory; they could compare recently-infected colonies with those free from the parasite, and paint a biological picture of exactly how Varroa affected the bees.
The team spent two years monitoring colonies – screening Varroa-infected and uninfected bees to see what viruses lived in their bodies.
Dr Martin explained to BBC Nature that most viruses were not normally harmful to the bees, but the mite “selected” one lethal strain of one specific virus.
“In an infected bee there can be more viral particles than there are people on the planet,” Dr Martin explained.
“There’s a vast diversity of viral strains within a bee, and most of them are adapted to exist in their own little bit of the insect; they get on quite happily.”
But the mite, he explained, “shifts something”.
By Glenn I. Teves, County Extension Agent, UH CTAHR Cooperative Extension Service
The relationship between humans and honeybees is ancient, as demonstrated by cave paintings in Spain, South Africa, and Nepal, depicting honey hunters collecting honey from wild hives. The honeybee was introduced to Hawaii in 1857, but the accidental introduction of the Varroa mite in 2007 puts this relationship in jeopardy and is one example of Hawaii’s vulnerability to invasive species.
The Varroa mite (Varroa destructor) is one of the most serious pests of honeybees and is associated with the spread of viruses and the decline of honey bee colonies on the mainland. And it’s only a matter of time before it destroys all feral honeybee colonies in Hawaii. On the island of Oahu alone, over 90 percent of the wild colonies have been wiped out and it has now moved to the Big Island, starting in Hilo. Visual checks of feral honeybees in Ho`olehua and Mo`omomi have not found the Varroa mite to date.
The mites attack both adult bees, and also larvae in the hive. Although honeybees in Hawaii are crosses between German, Italian, and Carnolian bees, the honeybees on Molokai appear to be a special disease resistant strain, first brought in around 1898. They show resistance to a disease called Foul Brood, which wiped out honeybees on most of the islands starting in 1908.
Posted on October 13, 2009.
Sydney Ross Singer
In case you haven’t heard the buzz, the honey bee in Hawaii is gravely threatened by a newly introduced parasite, the varroa mite, which can wipe out our bee population within a few years, and is spreading across the state.
The question is, should we save the honey bees, or is the mite doing us a favor?
If you ask residents, farmers, and beekeepers, the honey bee is a blessing in Hawaii. They provide delicious honey, they help pollinate all sorts of fruit trees and crops, and they are interesting creatures to raise as a hobby. For most people, our islands would surely be less sweet without honey bees.
On the other hand, if you ask some conservationists who only value “native” species and wish to eradicate introduced ones, the honey bee is an invasive species curse in Hawaii. They compete with native pollinators, and they pollinate alien plant species that are encroaching on native forests. For these people, conservation would best be served by the eradication of the honey bee.
Unfortunately, the Hawaii government holds both of these opinions. And this spells doom for the honey bee.
The bees and the trees (and tomatoes, cucumbers, melons, mac nuts…)
Special to Hawaii247 by Andrea Dean/Volcano Island Honey
Do you know that one-third of all the food you eat is pollinated by bees?
The decimation of bee colonies is a threat to food production in Hawaii. In Hawaii we do not have the disappearance of bees (Colony Collapse Disorder or CCD), but we now have the devastating and aptly named varroa destructor, commonly known as the varroa mite.
The varroa mite is a parasite that attacks honey bee adults, larvae, and pupae. The varroa mite has been know to destroy up to 90 percent of wild hives and beekeepers can easily lose all or a majority of their managed hives.
Until recently, Hawaii and Australia were the only remaining varroa free places in the world. The varroa mite was found on Oahu in 2007, unfortunately this did not result in quick and aggressive action by the private or government sector. As a result, the mite has now been found in hives on the Big Island.
HILO — 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 Hawaii, said Ethel Villalobos, an entomologist at the University of Hawaii’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 parasite.
"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."
From Jeffrey Parker and Masako Cordray Westcott of the Hawaii Agriculture & Conservation Coalition
Emergency Senate Hearing on the Dept of Agriculture layoffs – please testimony today!
Thursday, Sept 3rd, 5-9pm, Maui Waena School, 795 Onehee Ave, Kahului
CTAHR dean details impacts of ag. inspectors layoffs
Updated at 3:27 am, Thursday, August 20, 2009.
Andrew Hashimoto, dean and director of the College of Tropical Agriculture and Human Resources (CTAHR) at the University of Hawaii at Manoa, gave the following testimony to the Senate Ad-Hoc Committee about the potential impacts of laying off Department of Agriculture staff.
I am pleased to provide personal testimony relating to the potential impacts on the community and agricultural industry on the Big Island, arising from the anticipated reduction and possible elimination of the Hawaii Department of Agriculture’s Plant Quarantine Branch. This testimony does not represent the position of the University of Hawaii or CTAHR.
The Hawaii Department of Agriculture (HDOA) has 329 “permanent” employees, of which 118 (approximately 36 percent) have received notices for layoff.
The Plant Quarantine (PQ) Branch will be especially hard hit. It has a total of 78 inspectors and 16 technicians (aides).
Of that, 50 inspectors and two technicians (all general funded) have been given notices. The remainder (11 inspectors and 14 technicians) are paid from special funds.
Most of the inspectors to be laid off will be from the neighbor islands. Information on the number of layoffs for each of the other HDOA branches is not known. The impact of the layoff in the PQ branch is discussed.
Should the layoffs go forward in November as planned by Gov. Linda Lingle, not all Maui-based inspectors will disappear, according to Carol Okada, manager of the Plant Quarantine Bureau in the state Department of Agriculture.
There are inspectors in 10 positions covered by special funds who will not be affected, including six funded by the state Department of Transportation. But the six positions paid out of the state’s general fund are on the budget-cutting hit list.
Anna Mae Shishido, Maui County supervisor of the Maui Plant Quarantine Branch, wrote a letter expressing her concern about the impact of the layoffs to two Maui lawmakers – state Sen. J. Kalani English and Rep. Joe Souki.
She said the Transportation Department’s special fund specifies that the six inspectors it pays for would work at the Kahului Airport – which means they wouldn’t do maritime inspections.
As a result, Matson and other containers carrying produce, animal feed and other agricultural material would need to go to Honolulu first for inspection, Shishido said. Diverting that cargo to Oahu would mean extra handling of Maui-bound containers, adding delays and costs for consumers.
The layoffs would also mean that more than two dozen certified nurseries on Maui would no longer be able to self-certify their plant shipments to other states because state inspectors would not be available to conduct semi-annual nursery re-certification inspections, she said.
Shishido said she was alarmed about the potential for infestations of alien species without maritime inspections on Maui.
"We anticipate increased infestations of stinging nettle caterpillars and coqui frogs on Maui and new infestations of little fire ants and the varroa mite, which have not been found here so far," she said. "The safeguards we have worked so hard to put in place will be drastically decreased or completely gone. Maui will be exposed."