Bee Zaagar - Apiary and Beekeeping News

Nation's crops at risk as varroa mites kill off bees

Judy Nichols
The Arizona Republic
July. 6, 2005 - Jesse Cameron is looking for a deadly invader in his beehives on a piece of farmland in west Phoenix. Protected by a white cotton jumpsuit and yellow net veil, he fans smoke over a stack of white boxes that make up a colony, or hive, and lifts off the top box heavy with honeycombs.

He is looking for combs filled with bee larvae. If it's here, this is where he will find it. He scrapes some brood cells open. They're clean. He goes to the next colony. "Here's one," he says. "Here's a varroa mite."

Honeybees in Arizona and across the country are being decimated by mites in an onslaught that could threaten crops from cranberry bogs in New Jersey to melons in Arizona and the almond industry in California. Researchers are in a race to save them.

Up to half of the honeybee colonies in Arizona have been killed, said Gloria DeGrandi-Hoffman, research leader at the Carl Hayden Bee Research Center in Tucson.

Ken Orletsky, a beekeeper in Arizona since 1971 and former president of the Arizona Beekeepers Association, said the problem may be even more severe. "We had 90,000 colonies in the 1970s," Orletsky said. "I don't know if we could come up with 5,000 or maybe 10,000 now."

DeGrandi-Hoffman said the mite was originally found overseas and came into the United States sometime in the 1980s. "When we started looking for mites, we were finding them everywhere," she said. "The bee industry is very mobile. Colonies are moved around for pollination. And when beekeepers start a colony, they buy a package of bees that is mailed to them. So bees are shipped everywhere."

For years, chemicals on strips hanging in the hives kept the mites at bay. But now, the mites have developed resistance, and scientists are scrambling to find something to save the bees. "Varroa mites are the Number 1 challenge to beekeeping," DeGrandi-Hoffman said. "It's the front-burner challenge to every bee research center. It's very, very serious."

Best at pollinating

European honeybees were brought to the Americas by settlers who considered them an essential part of colonial life. "There was no sweetener other than honey," DeGrandi-Hoffman said. "And they used the wax for candles." They also pollinated crops, providing food.

Bees flit from blossom to blossom, gathering pollen in sacs on their legs and collecting nectar. Along the way, some of the pollen from one bloom sticks to another, allowing the plants to produce fruits, vegetables and seeds.

There are thousands of species of bees, many native to the Americas, but most are solitary, building tiny nests, creating a small pollen ball for food, laying one or more eggs and leaving.

Only a small percentage creates large colonies like the European honeybee, producing quantities of honey that can be harvested for humans and building permanent hives that can be moved around for predictable crop pollination.

The honeybees have become dominant in Arizona and across the United States; native bees cannot fill their role. "The population of wild bees is not as large, not as dependable," DeGrandi-Hoffman said. "You would have to hope the bees emerge and are active when you need pollination. Honeybees are active year-round. "When you move a hive into the almonds, you drop down 30,000 or 40,000 bees that immediately start foraging. They can't be replaced as a large-scale agriculture pollinator. "Without them, we would be in a world of trouble."

So far, crops are getting pollinated, but it's costing more for the beehives. Arizona beekeepers are getting calls to take their bees to places like Colorado and Nebraska. The fear is that someday, there won't be enough bees.

In Arizona, bees are used to pollinate seed crops like onions, broccoli and lettuce, and some cotton for seed. They are also used for citrus like tangelos, grapefruit, lemons and limes. "Basically anything you don't want to be seedless," DeGrandi-Hoffman said.

Nationally, they are used for apples, pears, watermelons, cherries, cantaloupes, strawberries, blueberries, blackberries, raspberries, peaches, kiwi, cucumbers, squash, peas and beans. Some plants can produce fruit without pollination, but they need it to produce seeds. Even the clover and alfalfa that feed cows depend on bees, so bees affect the supply of beef, milk and cheese.

How mites attack

The female varroa mite can be seen as a small reddish-brown speck against the white larvae of the bee. It slips into the cell after the bee egg is laid, before it is sealed by the worker bee. Inside, the mite lays its eggs. After hatching, the baby mites feed on the developing larvae.

They can kill or cripple the bee, which emerges with deformed wings or missing legs. "One goes in, three come out," said Brad Auten of Western Honey Inc. in Phoenix. "The mites breed and reproduce in six to eight days, so you can imagine how fast things change in a hive."

The mites also attach themselves to adult bees, sucking their lifeblood, earning the nickname "vampire" mites.

Auten said the mites are coming back faster now. "We do the mite killing in the winter when we're not producing honey," he said. "Usually, after a season, we don't see the mites until October or November. This year, we treated in January and February, and we started seeing them again in April." The mites can literally kill off a hive, he said. "In California, I heard real horror stories of 2,000 colonies reduced to 100," Auten said.

"In a hive of 70,000 bees, about 20,000 are fliers, the rest are house bees that have different tasks. "They live about six weeks in the summer, three to four months in the winter. They are continually repopulating. "When you have attrition to mites, and you start losing control of the hive in late August or September, you're in trouble. "They've got to develop a new nest to go through the winter. In November, you're trying to build up strength they need to go to California."

Almond industry

California and its almond orchards are the big time for bees.

In the 1700s, the nut trees were brought to California from Spain by Franciscan padres. Today, more than 6,000 growers cultivate a half-million acres of almond trees in the state, supplying 75 percent of the world's almonds. It is a $2 billion industry, with Europeans the largest consumers.

And it relies on bees. Lots of them. "Without the bees, they'll get 1,000 pounds of almonds an acre; with bees, 3,000 pounds," Auten said. Colonies from 30 states are shipped to California in February to buzz the trees.

When Auten started sending his bees in 1989, he was charging $28 a hive. Last year, it was $55 to $60. This year, as the bee shortage deepens, some beekeepers charged $150, he said.

Although the prices beekeepers can charge for pollination are skyrocketing, the opposite is happening with honey. Cheap imports from China and Argentina are being dumped in the United States driving down honey prices.

DeGrandi-Hoffman said the bee business is really splitting into two businesses, pollination and honeymaking. "The pollination business is increasing," she said. "Colonies are worth more now than ever before, driven mostly by the almond industry, which is putting in more acres every year. The prices continue to rise, making it a lucrative investment to get started.

"Honey production is tougher. Dealing with the price of honey is an international thing. Beekeepers are trying to fend off honey from other countries that dump it on the market. It's a continual political battle that happens with many crops, whether you're growing apples or honey."

Fighting the mites

Africanized bees, which are a somewhat more aggressive form of honeybee, seem better able to fend off the mites, chewing them off. "Someday we may be pollinating with Africanized bees," DeGrandi-Hoffman said. "But it will require a change in management practices because they're not as gentle as the European bees." But beekeepers say the Africanized bees have gotten a bad name through scare stories in the media. "On a good day, it's hard to tell the difference," Auten said.

At the bee research center, part of the U.S. Department of Agriculture, four scientists with an annual budget of $1 million are working to find natural compounds to combat the mites. Organisms usually don't develop immunity to natural compounds like they do to chemical ones. "You have to find something you can put into a colony that produces food products, something that won't contaminate the honey, the wax or the pollen," she said. "And it needs to kill the mites but not the bees.

"We certainly hope it comes in time."