There are reports of unexplained bee kills practically every beekeeping season. Symptoms are often diffuse. Bees with uncoupled wings (K- wing) and distended abdomens may crawl out of colonies or die with their heads in cells. Signs may be reminiscent of starvation, even when the colony has a good deal of honey and pollen left. The tracheal mite enigma also my be involved. Many times, all the beekeeper can point to is a catastrophic decline in worker population. These losses are some of the most difficult to grapple with for beekeepers and researchers alike. The situation is often complicated by environmental causes of loss, especially when pesticides are involved.
Similar phenomena fill the world apicultural literature, variously called “disappearing disease,” “Autumn collapse,” “May disease,” and “Spring dwindling.” More recently a new term “colony collapse disorder” or CCD has been trumpeted as the so-called “smoking gun” of unexplained honey bee losses. Unfortunately, the above terms are only descriptions of symptoms. They do not adequately address the root of the problem. The search for solutions must come, as for human illness, from a detailed history of the patient and situation.
In the meantime, beekeepers are urged to bear in mind the words of Dr. L. Bailey in his classic book, Honey Bee Pathology:
“A wide variety of specific pathogens are endemic in honey bees, and most of them are perpetuated as inapparent infections. Colonies, and even individual insects, that are infected with certain, sometimes several, pathogens frequently seem outwardly normal of an indefinite period. Accordingly, it is often difficult to identify the causes of losses and disorders, and this has led to much confusion and many false diagnoses; especially when some pathogens, particularly viruses, have gone unrecognized.
“The available evidence shows that honey bee pathogens multiply and spread to cause more damage than usual within those colonies that are most hindered in their development by adverse environmental events. Food shortage is the first result of these unfavourable conditions for bees in nature, and is often associated with an abnormal increase in pathogens. This is analogous to the nature of infectious diseases in other wild animal communities, in which severe disease is generally associated with food shortage and is a secondary cause of death.”
Unlike humans, bees can’t be asked to describe their symptoms. Therefore, the answers to many questions on which a solution might be based are only guesses. The best advice is to explore a number of avenues in the hope of arriving at a common answer that will be explanatory, realizing that it often will be multi-factorial in nature. One technique is to brainstorm in a group setting, writing down all the possible causes and symptoms. The list can then be selectively reduced to find the most likely causes.
If you suffer large-scale bee loss and can find little reason for it, carefully document the symptoms to be able to clearly communicate them to others. Include in the written description as much detail as possible about management decisions and environmental conditions that affect the situation. It is important to write the information down; verbal description leads to fuzzy thinking and cannot be referred to by others. Only by analyzing recorded observations, will researchers and beekeepers alike have a place to begin the difficult search for solutions to unexplained bee loss. A relatively new program is being used to examine bee losses, using the science of epidemiology, through what is called the Bee Informed Partnership.