Honeybees and humans share a long and productive alliance dating back more than three thousand years. Bees provide us with honey and wax. We provide them with shelter and food. What many people do not realize is the vital role honeybees play in pollinating more than 100 of our most important crops including apples, blackberries, citrus, almonds, cotton, soybeans, sunflowers, asparagus, broccoli, carrots, cucumbers, eggplants, lima beans, onions, peppers, pumpkins, cantaloupes, and watermelons just to name a few. The goods and services provided by our six-legged friends account for more than 14 billion dollars annually in the United States. Unfortunately, this year something malevolent visits the realm of honeybees.
Colony Collapse Disorder
All across America and in Europe as well, honeybees are disappearing. A mysterious phenomenon called Colony Collapse Disorder, a.k.a. CCD, has spread through the land. According to one account, this strange disorder appeared last spring in the Midwestern states of Michigan, Iowa, and Wisconsin and then moved rapidly from coast to coast. On the east coast, it has been found in several states from Florida to Connecticut. Many commercial beekeepers, especially those that move their hives from farm to farm to pollinate crops, have been particularly hard hit. Colony losses range from 50 - 90%. When you consider that each hive can contain 20,000 to 50,000 bees and many commercial growers maintain more than 1000 colonies, the number of bees lost to this mysterious disorder is well into the billions. The magnitude and geographic scale of this disorder are impressive, but one of the most fascinating aspects of CCD is the nature of the disorder itself.
Effect of CCD
A healthy honeybee colony consists of a queen capable of laying hundreds of eggs each day. She is attended by young hive bees that care for her and the developing larvae called brood. Thousands of older bees guard the hive and carry out the vital task of finding and gathering nectar and pollen to feed the busy colony. When CCD strikes, all of the workers, save a few of the youngest, simply abandon the hive and disappear in very short suspense. Without a work force, the colony cannot function. It rapidly collapses and "dies". Why do the workers abandon the hive leaving it stocked with food and young? Why do they abandon their mother the queen? Where do the honeybees go? Many unanswered questions surround this phenomenon. Even more curious is the fact that some bandits of beehives, wax moths and small hive beetles, avoid the abandoned colonies leaving valuable honey and brood to decay. Some strange sixth sense seems to warn even the robbers away.
Source of CCD
Several hypotheses have been erected to explain CCD. Many think that a new disease organism such as a fungus, protozoan, or virus has been introduced into the honeybee population and is rapidly spreading as commercial hives are moved about the country to pollinate our crops. Another possibility is that older known honeybee killers such as fungal disease called stonebrood caused by Aspergillis, or the protozoan, Nosema, may be rearing their ugly heads again. There is a suspicion that new insecticides widely used in agriculture and by homeowners have non-lethal effects on workers. These effects might cause workers to forage less efficiently thereby weakening the hive or pesticides may suppress the bee's immune system increasing their susceptible to disease. This effect could be compounded by poor nutrition due to low quality or insufficient pollen or by the continuing onslaught of debilitating parasites called varroa mites that suck the blood of bees. Stress may be another important factor. Greater demands have been placed on commercial honeybees as colonies are moved several times each year over long distances to pollinate different crops across the nation. Many scientists believe that a combination of these stress-factors, poor nutrition, pesky mites, pathogens, weaken the immune system of honeybees to the point that diseases become rampant and cause a colony to collapse. Some have suggested that global warming, cell phones, and genetically modified crops may be involved in CCD, but at the present time, there is little scientific evidence to support these notions. The best minds in the bee world recently met to discuss CCD and forge an aggressive research plan to understand how to manage this disorder. The USDA and dozens of scientists have pledged their support to help solve this mystery and save our age-old friend, the honeybee. Stay tuned as the mystery unfolds.
Most of the information for this Bug of the Week came from the fantastic Mid-Atlantic Apiculture website referenced below. Several references at this site were used for the story. I also thank Maryann Frazier of Penn State University for taking the time to share her ideas and knowledge. An interesting account by Dick Marron in the April 2007 issue of the American Bee Journal was also used as a reference. For more information on CCD, please visit the web site listed below.