Varroa mites are small, parasitic insects that infest honey bee colonies. They feed on the blood of the bees, weakening them and making them more susceptible to diseases. Varroa mites can also transmit viruses from one bee to another, further harming the health of the colony. The mites are a major threat to honey bees and are considered one of the leading causes of colony collapse disorder.
Varroa mites are parasitic insects that feed on the blood of honey bees. They attach themselves to the bees and puncture their bodies with their sharp mouthparts to feed on their hemolymph, which is the insect equivalent of blood. Varroa mites are known to feed on both adult bees and larvae, but they prefer to feed on the latter because the larvae are more vulnerable and provide a richer source of food. In addition to feeding on the bees’ blood, varroa mites can also feed on the bees’ eggs and pupae, further harming the health of the colony.
Varroa mites are known to transmit several different viruses to honey bees, including deformed wing virus and acute bee paralysis virus. These viruses can cause a range of symptoms in infected bees, including deformed wings, paralysis, and death. In addition to these viruses, varroa mites can also transmit other diseases and parasites, such as bacteria and fungi, that can harm the health of the bee colony.
Deformed wing virus (DWV) is a viral infection that affects honey bees. It is transmitted by varroa mites, which feed on the bees and transmit the virus from one bee to another. Infected bees develop deformed wings and are unable to fly, which makes it difficult for them to forage for food and carry out other essential tasks within the colony. This can lead to a decline in the overall health of the colony and can contribute to colony collapse.
Cause: The parasitic mite Varroa destructor
Symptoms: Presence of adult mites, deformed wings
- Highly associated with colony loss
- Original host: Apis ceranae
- Feed on bee fat stores (brood and adults)
- Reproduce in brood cells
- Preferentially attacks drone brood
Vectors virus diseases
Suppresses immune response
Mite Detection
Sticky boards
- Non-invasive
- Leave sticky board on for 24 hours and record the number of mites
- Threshold for treatment:
- 60-190 mites dependent on colony size
Alcohol wash
- Collect ~300 bees and “wash” the mites off the bees
- Calculate mite/bee ratio
- Threshold for treatment: Varied but usually 3 mites/100 bees although some beekeepers now recommend 1% threshold (this needs more research)
Sugar Roll
- Non-destructive
- Collect ~300 bees and dislodge mites off the bees
- Calculate mite/bee ratio
- Threshold for treatment: Varied but usually 3 mites/100 bees
Drone brood inspection
- Inspect the drone pupae adult varroa mites.
- Threshold for treatment: Mites on 10 % or more of drones
Varroa Mite Non Chemical Management
Resistant/Hygienic stock
- VSH
- Minnesota Hygienic
- Russian
Drone Comb Removal
Brood Break
- Split
- Swarm
- Cage Queen
IPM Bottom Boards
Varroa Mite Chemical Management
Synthetic
- Apivar (Amitraz)
- Check Mite (Coumaphos –used primarily for SHB control)
- Apistan (Fluvalinate)
Bio-pesticides
- Oxalic Acid (not yet legal in CA)
- Essential Oils (e.g., thymol)
- Formic Acid
- Hop Beta Acids (Hop Guard II)