Honey bees are no different than other organisms. They are challenged by diseases and pests and must deal with them using their own biological mechanisms. The majority of bee diseases and pests attack only one stage of the honey bee’s life cycle. This confers an advantage, providing diversity in ways bees can are protected by their own biology . The Varroa bee mite, is so damaging because it attacks all honey bee life stages: larva, pupa and adult.
Traditionally topping the disease list for honey bees are two types of bacterial diseases called “foulbrood,” because they result in disintegration of the larvae/pupae, collectively called the “brood,” resulting in a foul mess and odor. These are often called stress diseases and include two more that are considered fungi, known as chalkbrood and Nosema.
A number of mammals are considered pests of beehives, including skunks, possums and others. But the black bear is often the most notorious and difficult to control.
Two mites (acarines) have recently been introduced to European honey bees in the U.S. These eight-legged creatures have dealt some significant blows to beekeeping. The first to make its appearance was the tracheal mite in 1984. On the heels of this, the Varroa mite was introduced in 1987, and still is considered the most problematic organism facing honey bees and beekeepers today. Although something that has been used with success in other agricultural endeavors, the use of biological control at the moment is not considered feasible for these mites. Another organism is also considered introduced in North America is a variant of the Western honey bee, now called the Africanized honey bee.
The small hive beetle introduced in 1998 from South Africa is the newest “invasive” pest. It now compliments a traditional scavenger that beekeepers know well, the wax moth. There are several insect predators that can be extremely damaging to colonies as well.
Although there are plenty of viruses around, honey bees have historically been challenged by relative few. However, have become a more important topic with beekeepers and researchers now that the Varroa mite has been determined a major vector due to its feeding behavior.
As more and more problems become associated with bee hives, the topic of comb renovation is taking center stage as is the concept that some honey bees are more hygienic than others. In the same vein beekeepers should not loose sight of the fact that honey bees have a good deal of internal defense mechanisms. Many times beekeepers unwittingly mitigate these through active manipulations, when the best strategy is to leave the bees to handle it themselves.
Many conditions fall under the rubric of “unexplained bee kills,” that appear to have no definitive causes and may be multi-factorial in origin. This fits well with what has been called “the nemesis effect.” With this further complexity, making beekeeping much more difficult than in previous times, the idea that beekeepers should look into a professional diagnostics service is gaining traction.
Biological control of pests and diseases remains the holy grail in honey bee research and there have been some advances, but much more remains to be done. An interesting turnabout is the use of honey bees to deliver biological control agents, including various fungi. This might open up a new “service” honey bees and beekeepers could provide.