Glossary
A parasitic mite (Varroa destructor) that feeds on the fat bodies of honey bee brood and adults, spreading viruses and weakening colonies. Varroa management is one of the biggest challenges facing modern beekeeping worldwide.
Varroa destructor is a reddish-brown, crab-shaped mite about the size of a pinhead. It originated in Asia, where it parasitized the Asian honey bee (Apis cerana) in a relatively balanced host-parasite relationship. When the European honey bee (Apis mellifera) was introduced to Asia, varroa jumped species. The European honey bee had no evolutionary defenses, and when infested colonies were shipped around the world, varroa went with them. By the late 1980s, varroa had spread to every continent except Australia.
Female varroa mites reproduce inside capped brood cells. A mother mite enters a cell just before it is capped, hiding in the brood food. Once sealed inside, she lays eggs on the developing bee pupa. The young mites feed on the developing bee's fat body (an organ that serves functions similar to a mammalian liver). By the time the adult bee emerges from the cell, she has already been drained of nutrients and may be carrying viruses transmitted by the mites.
The most damaging of these viruses is Deformed Wing Virus (DWV), which causes bees to emerge with shriveled, non-functional wings. Heavily infested colonies show a visible decline: the bee population shrinks, honey production drops, and the remaining bees become lethargic and disoriented. Without treatment, most infested colonies collapse within 1 to 3 years.
No beekeeper has eradicated varroa. The goal is management: keeping mite populations below levels that threaten colony survival. Methods range from chemical treatments (miticides like formic acid and oxalic acid, which are organic acids approved for use in beekeeping) to mechanical methods (drone frame trapping, powdered sugar dusting) to breeding programs that select for hygienic behavior in bees.
In Florida's warm climate, varroa pressure is relentless because brood rearing never fully stops. Northern beekeepers get a natural brood break in winter that interrupts the mite's reproductive cycle, but our bees raise brood year-round, giving varroa no off-season. This makes monitoring and treatment timing critical for every Florida beekeeper.
Yes. Left untreated, varroa mite infestations will typically kill a colony within 1 to 3 years. The mites weaken individual bees and transmit viruses like Deformed Wing Virus that cripple the colony's ability to function.
The most common method is an alcohol wash or sugar roll test, where a sample of about 300 bees is collected and tested for mites. A threshold of 2 to 3 mites per 100 bees usually triggers treatment. Regular monitoring is essential because infestations can grow exponentially.
Varroa mites do not directly contaminate honey, but heavily infested colonies produce less honey because the workforce is weakened. Healthy, well-managed hives with low mite loads produce significantly more surplus honey than struggling colonies.
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