One of the greatest threats to honey bees in the northern hemisphere is the Varroa mite. Known as the vampire of the bee world, the destructive parasites feed on bee blood and reproduce on bee brood, spreading viral diseases such as deformed wing virus and chronic paralysis. Mites are vectored by bees which can then spread them from hive to hive.
Not only are Varroa mites recognized as a major factor causing colony loss in the United States and other countries, they also affect bee immune systems and vector several debilitating viruses.
The destructive parasites affect almost all honey bee colonies. The pest invaded North America in the 1980s and today only Australia is still Varroa-free, making it the continent with some of the healthiest Western honey bees on the planet.
The mites attack honey bees at all life stages – from brood to adults – and feed off them, which weakens and shortens their life span. Just imagine a large insect the size of a dinner plate sucking blood from your back while transmitting diseases! That is exactly how honey bees are affected by the Varroa mite. If left untreated, the mites may kill the entire bee colony.
Infested brood may be deformed with missing legs or wings. Untreated infestations of Varroa mites may ultimately kill honey bee colonies. Varroosis treatment depends heavily on a small portfolio of varroacides. Unfortunately, resistance to most of them has already been reported. As a consequence, beekeepers and authorities are seriously concerned about the availability of veterinary products for bees.
See more about pests and pathogens impacting honey bee health under “Bee Health Stressors