Local beekeepers do battle with a devastating parasite

| 21 Feb 2012 | 10:59

    Local gardens and farms are greening up. Soon, local produce will be everywhere, from the shelves of supermarkets to roadside stands and farmer's markets. But imagine walking into that supermarket only to find the shelves bare, or stopping at the roadside stand only to find it boarded up. Imagine, too, the cost of fresh produce rising as fast as the cost of gasoline. This is the scenario scientists and beekeepers say could be a consequence of an epidemic devastating hives across the United States. The culprit is Varroa destructor, a parasitic mite that originated in Southeast Asia. This, industry specialists say, could be disastrous for American farmers and consumers. Honeybees are an inconspicuous yet crucial cog in the wheel of agribusiness. Honey and "hive products" account for $250 million in annual revenue for beekeepers and other associated industries. More staggering is the bees' contribution to the $14.6 billion industry of fruit crops, including cranberries, blueberries, almonds, apples, pears, avocados, cherries, and many more. Honeybees are active from early spring through late fall, often relying on several different blooming seasons to gather the pollen they need to make honey. Along the way they do the essential job of pollinating crops. Since World War II, American farmers have increasingly shifted from multi-crop farming to mono-crop farming. Most farms are now single-crop, but bees cannot survive through spring, summer, and fall in one location. So beekeepers adapted, moving their hives to the orchards to help farmers with different crops. Beekeepers can operate in many different parts of the country, moving with the seasons. As recently as this spring, California almond farmers felt the effect of the Varroa mite on honeybees. Commercial beekeepers there opened their hives after winter to find massive losses due to mite infestations. The entire crop of almonds, the first to bloom during the growing season, was threatened by a shortage of bees. According to the American Beekeeping Federation, several farmers imported bees from as far away as Florida to help pollinate the crop, which requires at least 1 million colonies to pollinate successfully. Without bees, pollination does not take place, and plants do not produce fruit. The U.S. Department of Agriculture states that a full one-third of the average American diet depends on insect-pollinated plants. Local apiculturist Marcel Witschard from Montgomery, N.Y., sums this up succinctly by asking: "Do you like apples? Do you like pears? Peaches? Well, every fruit you eat must first be kissed by a bee!" Witschard's yard and garden are a testament to this. There, bees can choose from a variety of pears, apples, grapes, tomatoes, and wildflowers. Mike Stanghellini, Ph.D, an apiculturist with the Department of Extension Specialists at Rutgers University in New Brunswick, N.J., explained that during the early 20th century, European farmers in colonial in Southeast Asia often shipped honeybees to there in the hope of boosting crop potential by increasing the rate of pollination. The Asian honeybees, Apis cerana, have a much more symbiotic relationship with the mites that never had any great affect on hive health. However, the European honeybees, Apis mellifera, had never been exposed to the Varroa mite, and therefore had no defense for it. Within 30 to 40 years, Stanghellini said, the mites had migrated all the way through to every European country. Most beekeepers in the United States knew it was only a matter of time before the mites made their way here. In 1987, beekeepers in Wisconsin reported sighting the mites. Almost simultaneously, they were found in Florida. Within three years the mites migrated across the entire continent. The effect was catastrophic. Pre-mite estimates of honeybee populations were anywhere between 4 and 4.5 million colonies, but by 2000 estimates dipped to 2.4 million colonies. They have dropped below 2 million since, Stanghellini said. The mites attach themselves to both adult bees and brood. They then feed off the blood of the bees, resulting in weakened bees and deformities. Colonies with weakened bees are less likely to make it through normal hardships that strong colonies can typically endure, like harsh winters and invading bees. Tom Webb, a beekeeper from Wantage, N.J., who lives near Greenville, N.Y., began to notice mites in his colonies four to five years ago. "It was expected that they'd be here," he said. "Winter losses around here would be something like 5 percent, but after the mites showed up, it's now around 50 percent, and that is a good year." Treatments were effective at first. Mites were controlled with a pesticide that did not harm the bees or the honey if used correctly. This pesticide, Apistan, was applied after the honey was collected from the hives. Then, about three years after its commercial use was approved, mites began showing resistance to Apistan. Several other pesticides have been used since, each showing some initial promise. But the mites soon became resistant. "In the last few years, there has been a big movement away from conventional pesticide use," said Stanghellini. "Apiculturists are using essential oils, like eucalyptus, with some effectiveness." He also noted that the agriculture department has increased research into finding genetically resistant strains of honeybees, like those of Southeast Asia and Eastern Russia. Those bees, he said, have had a longer contact period with the mite and so have genetically eliminated bees that could not handle the mite's damage while retaining vigorous bees. Among the thousands of bees housed at Witschard's colonies, he pointed out this very fact. "Those there, the dark ones, they are the Russian bees," he said. "Very hearty bees, they are." Witschard's bees range from bees he himself has raised, as well as those he has rescued through a service in Orange, Ulster, and Dutchess counties. Mixing these bees with the bees from Russia and Italy, he has had some success against the mites. He, like Webb, uses what is known as a screened bottom board on the base of his colonies. This is simply wire mesh that sits two inches from the base of the box. When the bees groom themselves, which they do meticulously, the mites often fall off and onto the base of the colony. The holes in the screen are small enough to allow the mites, but not the bees, to pass through. Below the screen, Witschard puts a sticky substance, usually Crisco, to trap the mites. This system can help control a minor mite infestation, but chemical treatments are needed for massive ones. Both Witschard and Webb have begun to use formic acid, which has no ill affect on either bees or honey quality but requires proper ventilation. A study done by Stanghellini and two colleagues from Rutgers showed a success rate of nearly 80 percent. This is promising news. But for beekeepers like Witschard and Webb, the cost of keeping bees continues to rise. "Beekeepers will have to do what works for them," said Witschard, "I like to let them (the bees) do my job for me and try to leave them alone as much as possible." "We've got to be very careful what we put in the hives because we have to protect the honey," said Webb. "It used to be that you would spend a total of 20 minutes a year on each colony you owned," said Stanghellini. "Now that has increased tenfold. And the cost for beekeepers has now risen to nearly $10 to $20 per colony." That may work for small beekeepers like Witschard and Webb, but some commercial beekeepers in the New York and New Jersey area have nearly 3,000 colonies. While local beekeepers do not have nearly that number, they do feel the pinch financially. But the rewards, they say, are worth it. "Be good to them, and they'll be good to you. It's nature!" said Witschard. "Everyone says, ‘Marcel, you are crazy!' and they are right, I am, but that is why I do this — for the bees."