Intermediate Beekeeping 201 Lesson Three
Diseases of Adult Bees
Nosema Disease
The very first adult bee disease we are going to discuss is nosema. It is caused by a protozoa called Nosema apis. Doctor Tom Webster of Kentucky has indicated that most likely, more bees die out over winter from nosema than anything else. It is also one of the diseases we as beekeepers overlook most often. As with all diseases of the honey bee, the colony will have a reduced ability to gather and save much honey so the beekeeper will have reduced honey production from the bees.
Nosema spores are ingested by adult bees. They germinate in the gut of the honey bee where they grow and multiply. During the process mature nosema infected cells rupture and become commingled with the feces. Bees do not normally defecate in the hive. The beekeeper will often discover this disease when examining the hive in the early spring. The top bars will be covered in a brownish-yellow watery material from defecating bees within the hive. One might also see what I call tobacco stains of bees defecating on the front of hives. However, the only positive way to identify this disease is the microscopic examination of adult bees.
"Heavily infected bees are unable to properly digest their food as the epithelial cells of the mid-gut have been damaged by the disease organism. Such bees have shortened life spans and, as they cannot digest pollen, are unable to produce the protein-rich brood food (royal jelly) need by larvae. In fact, the hypophryngeal glands responsible for brood food production are seen to atrophy or disintegrate in heavily diseased bees. This results in poor spring build-up, or a population decrease in severe cases. Queens may also be superseded in Nosema-infected colonies." From Honey Bee Diseases and Pest, produced by the Canadian Association of Professional Apiculturists. This would be a worthwhile publication to have in your library. It is available from Walter T. Kelley Co.
Click here For information on Nosema
Mites: Varroa and Tracheal
Nothing has had quite the impact on beekeeping as the introduction of these two mites into the United States. As the mites spread through the U.S., Canada closed its borders to imported package bees from the United States. However, mites spread to the entire North American continent. At the time of this writing, Hawaii does not have mites but they have just recently been discovered in other island continents.
Many university apiary programs began to investigate mites during the 1990's. These programs have worked with developing controls for the mites as well as beginning breeding programs to improve breeding stock resistant to the mites. So far, no bee is totally resistant to Varroa mites but success has been achieved in the battle against tracheal mites.
Dr. Diana Sammataro did a considerable amount of research on the formulation of sugar and grease patties for tracheal mite treatments as she worked on her PhD. at Ohio State University. This is a formulation in common use today.
We are going to present some very interesting information to you. Most of it comes from the bee journals of the 1980's when these pest showed up in the U.S.
The tracheal mite was first brought to our attention when starting in 1904 a large number of colonies of bees on the Isle of Wight began to die off. By the early 1920's a scientist by the name of J. Rennie had described Acarapis woodi as the culprit. It wasn't until the 1980's that it was officially found in the U.S.A.
From the June 1984 issue of The American Bee Journal under "What's Buzzing" -- Strike Force Swarms To Georgia An elite government strike force that helped stop the Mediterranean fruit fly that plagued California in 1980, descended on South Georgia in late March to stop an imaginary invasion of bees carrying destructive mites. "It keeps us ready in case something does happen,"said federal agriculture agent B.J. Lewis, a member of the 4-year old U.S. Department of Agriculture's Preparedness for Emergency Plant and Pest Actions. None of the 44 team members summoned to Georgia knew in advance that the program was just practice. Within 48 hours, they were at the Federal Law Enforcement Training Center near Brunswick, Ga. The hypothetical problem involved a swarm of bees carrying destructive parasites. In this scenario a swarm carrying Varrroa mites had come into this country on a ship. In reality neither Varroa or Acarapis mites have reached the United States. However, the Acarapis mite has been found only 150 miles from our border in Mexico. The Southern package bee and queen industry, at least, can be partially consoled by the fact that U.S. officials are aware of the threat and are preparing themselves for emergencies. (Rollin Moseley)
So much for June 1984. No mites reported in the U.S.
From the August 1984 issue of The American Bee Journal under "What's Buzzing" Acarapis woodi Mites Found in three Texas Locations; Beekeeper Cooperation Praised.
Acarapis woodi mites have been discovered near Weslaco, Texas, a town in extreme southern Texas, Harris County, southeast of Houston and Pecos County in West Texas. All three finds were from bees owned by the same apiarist. The original samples of suspect bees were taken during a routine inspection July 3 by a Brownville inspector who immediately sent them to the USDA Bioenviornmental Laboratory in Beltsville, Md. There, Dr. H. Shimanuki and his staff confirmed that the bee samples were, indeed, infected with Acarapis woodi mites. Apparently, the commercial beekeeper, Waylon Chandler Apiaries of Weslaco, also raised queens for sale and had over 60 hives right along the Rio Grande which he wanted inspectors to check. This is where the mites were found.
August 1984 -- First confirmed find for Acarapis woodi.
From the November 1984 issue of The American Bee Journal under "What's Buzzing" Acarine Disease Confirmed in South Dajkota, New York, North Dakota and Florida. "The tracheal mite was originally found in Texas and shortly thereafter in Louisiana. These new finds bring to six the number of states with confirmed tracheal mite findings. The article goes on but in all cases, the tracheal mites were found in commercial operations that moved bees out of Texas or Florida.
The extent of the spread is shown in the following map from the November issue of the American Bee Journal.
And so began the spread. If you are asked "how did we get these mites?" You now can explain where it began in the U.S. and how it was spread so rapidly.
Varroa jacobsoni were first discovered in the U.S. in September of 1987. They were first identified in a Wisconsin apiary and by May of 1988 the following states had confirmed finds of Varroa mites. (Florida, Illinois, Maine, Michigan, Mississippi, Nebraska, New York, Ohio, Pennsylvania, South Carolina, South Dakota, Washington, and Wisconsin. An attempt was made to quarantine the states where Varroa was found Federal Register/Vol. 53, No.69/Monday, April 11, 1988/Rules and Regulations for the Department of Agriculture Animal and Plant Health Inspection Service. It attempted to "restrict the interstate movement of regulated articles from the quarantined areas."
As all of us know the quarantine did not stop the spread of Varroa mites and by the early 1990's it was well established in almost all states. Just like the tracheal mite spread, Varroa was most likely spread by commercial pollination beekeepers. The rule to follow today is, treat for both mites. There are both chemical and non-chemical methods of treatment.
Click here for information on Varroa mites
Click here for information on Tracheal mites
Pest:
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Click here for information on Small Hive Beetles
This lesson should provide you with basic information on the diseases and pest of the honey bee. You should consider adding a good book on pest and diseases to your library. We have skimmed the subject and much more information is available.