Ecology And Environment

Where have all the Honeybees gone

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"Where have all the Honeybees gone"
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Entomologists are studying the reasons behind an enormous bee die off happening across the country. Golden honeybees are essential for pollinating wild plants, as well as up to 90 percent of all U. S. crops, says Dewey Caron, a Professor of Entomology and Applied Ecology at the University of Delaware and chairperson of the Eastern Agricultural Society (EAS). Pests such as the tracheal mite and the varroa mite are wiping out entire bee colonies, according to Caron. In the winter of 1995-96, beekeepers reported die-offs ranging from 40 percent in Pennsylvania to 80 percent in Maine as indicated by Scott Camazine, Assistant Professor of Entomology at Pennsylvania State University. He indicated that both mites and varroa mites feed on bee blood. Tracheal mites infect the breathing tubes of bees, which varroa mites resembling light brown poppy-seeds-camp on their victims` backs, often bringing disease with them.

Caron states that in the wild, "only 10 percent of all feral honeybee colonies remain within the northeastern United States." Caron has worked in the University of Delaware's 50-year-old apiary or bee farm and much biodiversity has been lost. A Fund for Rural America grant, awarded by the U.S. Department of Agriculture (USDA) and directed by Penn State, Caron will join beekeepers and researchers with the USDA's Beltsville, Maryland, beekeeping lab, as well as state departments of agriculture from Pennsylvania, Delaware, Maryland and New Jersey to develop new strategies for fighting mites.

Don't be afraid of the buzz of a bee. If it wasn't for bees, many fruits and vegetables we enjoy wouldn't exist. They are vital for pollination of plants, but lately, they've been disappearing by the billions, possibly putting food supplies at risk. For fruit and vegetable farmers, bees are "the only manageable pollinator," capable of doubling crop yields, say Caron, winner of a 1998 University of Delaware excellence-in-teaching award. They also benefit many native plant species. "All the crocuses in the spring, goldenrod in the summer and yellow flowers in the fall depon on the bee for pollination," Caron says.

"Bees are needed for the food we eat, for the color and the variety that's on our plates." Bees are dying by the billions, a problem which is threatening to wipe out crops dependent on bees for pollination. This starts fertilization that helps the plant grow seeds that turn into the food we eat. Fewer bees could cost us more at the grocery store, Caron says.

Jay Eavan, Ph.D., a geneticist from the U.S. Department of Agriculture, says, "What is so striking is the suddenness with which the bees disappeared." Entomologists call the mass disappearance, colony collapse disorder, or CCD. Research to solve the mystery of exactly why these mite-infested bees are dying. The question is asked by Camazine, "Do the mites directly damage worker bees?" Do they spread viral infection or weaken the bees' immune system, allowing other diseases to kill the colony? Do mite-infected bees have lower cold tolerance? All of this knowledge could help to develop new control strategies or to identify desirable traits to select for in breeding programs. Other studies are required to be conducted to evaluate whether specific lines of honey bee stock are resistant to mites."

Beekeepers can kill varroa mites by using a chemical miticide, apistan, within affected colonies. Some people don't want to use chemicals, either for environmental or economic reasons, Caron reports. Mites inevitably develop resistance to chemicals, this prompts the beekeepers to boost the dosage. Too large of a dosage of miticide can kill the bees as well as the mites, since both are arthropods. The young bees are particularly vulnerable to the miticide.

In a search of a longer-term solution, Camazine, Asst. Prof. of Entomology at Penn. State University, uses high-powered microscopes and other laboratory instruments to learn containing formic acid-a natural component of honey. Formic acid, legalized for mite treatment in Canada, does kill mites, but it evaporates quickly and, therefore, must be reapplied frequently. A formic acid gel may provide beekeepers with an important new alternative to Apistan, as it slows the rate of release of the chemical. Camazine says his group is studying essential oils, such as eucalyptus, as a possible natural mite repellent in the northeastern region.

Caron says, His research has shown that the price tag on a jar of honey can vary dramatically , but it's still a bargain. "Honey isn't essential for the human diet," Caron also said, "but most of us love that sweet taste. And, honeybees are a critical species for pollinating food and decorative plants. We need to do what we can to make sure they continue to thrive."

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