Crop pollination threatened in some areas, which could lead to crop failures

By Matt Bewley | The Daily Journal

Published Thursday, April 19, 2007

In the last six months, more than 35 percent of the U.S. population of the Western honey bee, required for food crop pollination across the country, have disappeared, leaving their hives to die and crops to fail.

“Colony Collapse Disorder (CCD) has hit especially hard on the East Coast,” Mark Sundberg of Sundberg Apiaries in Fergus Falls said. “There are a lot of different theories, but I know they’ve had extremely dry conditions, and when that happens, the queen stops laying (eggs) earlier than normal, so there were no replacements for older bees as they die off.”

To date, scientists have only identified the symptoms of CCD.

The cause of the phenomenon remains a mystery, though some say it is no more than a spike in the number of hive deaths, a common occurrence over the past 30 years.

Sundberg reported a 65-percent loss of his hives slated to go to California to pollinate almond crops there. The bees are responsible for 100 percent of the crop pollination so without the bees there simply will be no crop.

Still, Sundberg is skeptical.

“We don’t figure what we’re seeing has anything to do with CCD,” he said. “We now believe the Varroa mite was causing most of our losses, which came last fall. It’s my opinion that that’s what happening in a lot of cases.”

Varroa mites can only replicate in a honey bee colony. The mites attach to the body of a bee and weakens it by sucking its internal juices and spreads viruses to the bees.

A significant mite infestation will lead to the death of a honey bee colony, usually in the late fall through early spring.

The mites were inadvertently introduced into the U.S. in the 1980s.

These maladies weaken colonies and can lead to the collapse and death of colonies. Control has become increasingly difficult because the diseases and mites have developed resistance to some of the treatments.

Because of this, the Varroa mite has been the parasite with the most pronounced economic impact on the beekeeping industry, and been called a “contributing factor” to CCD.

Another symptom found in hives hit by the disorder is that adult workers simply fly away and disappear, leaving a small cluster of workers and the hive's young to fend for themselves.

A possible clue may be taken from the fact that nearby predators, such as the wax moth, are for some reason resisting from their typical behavior — moving in to pilfer honey and other hive contents from the abandoned hives. The CCD-affected honey remains untouched.

Honey bee colonies in the U.S. are overworked and under-appreciated.

They are the world’s most important pollinators of many fruits, vegetables and seed crops, contributing billions of dollars in value to agriculture and our diet, according to Marla Spivak, an entomologist specializing in apiculture with the University of Minnesota Extension.

Science continues to grapple with these bits of information, while across the 24 states affected, claimed losses by some apiary owners range up to 90 percent.

New treatments are currently available that reduce the risk of the pests developing resistance.

“Fortunately, colonies that die from diseases and mite parasites can be replaced with nursery stock,” Spivak said. “But overall, the number of bee colonies and beekeepers in the U.S. has been drastically reduced over the last 20 years.”