Varroa Mite IPM

A publication by the Massachusetts Department of Agricultural Resources-Apiary Program (MDAR), the University of Massachusetts-Amherst Extension (UMass), and the Maine Department of Agriculture, Conservation and Forestry (MDACF)-Apiary Program.

What is IPM?

Integrated Pest Management (IPM) is a proactive, science-based approach to managing pests, parasites, and pathogens that emphasizes prevention, routine monitoring, and informed, timely intervention to protect health while minimizing risk.

For Varroa mite management, IPM focuses on maintaining healthy, resilient colonies through informed decision-making. Beekeepers are encouraged to understand the pest by learning Varroa biology and its impact on honey bees, prevent population buildup through sound hive management, and monitor regularly to track mite levels throughout the season. Monitoring results then guide when to intervene as needed, using a combination of non-chemical practices (mechanical and cultural) and, when appropriate, chemical (pesticide) treatments. This integrated approach supports effective mite control while reducing colony stress, slowing resistance, and minimizing risks to bees, beekeepers, and the environment.

Effective Varroa management works best as a step-by-step process rather than a single action. Each stage builds on the last—starting with understanding the pest, then reducing risk through preventative practices, tracking populations over time, and taking action only when necessary. The following principles provide a clear, practical framework for decision-making throughout the season:

1. Understanding Varroa Mites: Know Your Pest — Learn the biology and behavior of the Varroa mite
2. Preventing Varroa Mites: Non-Chemical Practices — Reduce population buildup using non-chemical practices
3. Monitoring Varroa Mites: Alcohol Wash Sampling — Sample regularly to track mite population levels
4. Treating Varroa Mites: Intervene With Chemicals — When populations reach damaging thresholds, treat with appropriate chemicals, as needed

1. Understanding Varroa Mites: Know Your Pest

The Varroa Mite

The Varroa mite (Varroa destructor) is an external parasite that feeds on both adult honey bees and developing brood. As mites reproduce within capped brood cells and feed on bees’ fat body tissue, weaken individual bees, reduce lifespan, and impair overall colony health. Varroa mites also spread harmful viruses, which can also accelerate colony decline.

When mite populations exceed established treatment thresholds, damage can escalate quickly—virus levels surge, brood viability declines, and large numbers of weakened or deformed bees emerge. This leads to a shrinking workforce, poor foraging, and reduced ability to maintain the colony. If left unmanaged at these levels, colonies often experience rapid collapse, often in late summer or fall, even when food stores appear adequate. In many cases, high fall mite loads contribute to winter dead-outs, where colonies fail to survive the winter despite having sufficient food (i.e. bee bread and honey) stores—Varroa and the viruses they spread are a leading underlying cause of these losses.

Recognizing these impacts early is key. The following are common signs of Varroa-related damage that may be observed within the hive:

Common Signs of Mite Damage

• Brood:
  • Damaged pupae and abnormal brood cells
  • Patchy, spotty, or declining brood patterns
  • Half-chewed or missing pupae inside cells or on bottom board
  • Sunken or perforated cappings (can resemble other brood diseases)
  • Increased mite presence when uncapping drone brood
• Adult Bees:
  • Deformed adult bees (e.g., shriveled or missing wings, shortened abdomens)
  • Increased presence of crawling bees unable to fly
  • Bees with reduced vigor or disoriented behavior
  • Reduced adult bee population or dwindling workforce
  • Shortened lifespan leading to rapid population turnover
  • Visible mites on adult bees or within brood cells (often indicates a severe infestation and future sudden collapse)
• Colony:
  • Poor colony buildup, slow spring growth, or failure to thrive
  • Increased susceptibility to other stressors (disease, poor nutrition, environmental stress)
  • Sudden or late-season colony collapse, often with a small cluster and remaining food stores
  • Winter dead-outs with bees absent or in a small cluster despite adequate honey stores
  • “Parasitic Mite Syndrome” symptoms (combination of viruses, brood issues, and population decline)

2. Preventing Varroa Mites: Non-Chemical Practices

Preventing Varroa mite population buildup is a critical second step in effective IPM. By using consistent, non-chemical management practices throughout the year, beekeepers can reduce mite pressure, limit spread between colonies, and support overall colony health—often delaying or reducing the need for chemical intervention. 

The following seasonal strategies provide practical ways to implement these preventative practices in your apiary:

All Year

• Hive Differentiation: Reduce mite transmission from drifting bees by increasing spacing between hives and varying hive colors, entrances, and orientations.
• Screened Bottom Boards: While research shows mixed results for direct mite control, screened bottoms can help dislodge some mites and improve hive ventilation and moisture management.
• Apiary Management: Avoid overcrowding, maintain strong colonies, and limit unnecessary movement of frames or equipment between hives to reduce mite spread.
• Equipment Sanitation: Clean tools and avoid sharing equipment between colonies unless necessary to limit pest, parasite and pathogen transfer.
• Remove Weak or Expired Hives: Weak or failing colonies can become mite reservoirs so consider removing them from the apiary to reduce spread. Do not leave exposed equipment or comb from expired or dead-out hives as this can promote robbing and increase the risk of spreading pests, parasites, and pathogens between hives and apiaries.

Spring and Summer

• Re-Queen: When possible, select and introduce queens from mite-resistant or hygienic stock to improve colony resilience.
• Brood Interruption: Temporarily interrupt brood production—through splitting colonies or caging the queen—to break the Varroa mite reproductive cycle.
• Drone Brood Removal: Because Varroa mites prefer drone brood, this technique can be used to “trap” and remove mites:
  • Insert a foundationless, medium frame in a deep frame box or a drone frame into the hive
  • Allow bees to draw comb, the queen to lay eggs and drone brood to become capped (approximately 2–3 weeks)
  • Remove the frame and cut out or freeze the capped drone brood
  • Return the frame to the hive to repeat the process
• Robber Screens: Install screens to reduce robbing and drifting, both of which can spread mites between colonies.
• Maintain Strong Colonies: Ensure adequate nutrition (especially during nectar dearths) so colonies are better able to tolerate and recover from mite pressure.
• Limit Drifting During Moves: When moving hives, reorient entrances or use landmarks to reduce drift between colonies.

Fall

• Reduce Colony Stress: Minimize disturbances and ensure adequate food stores so colonies can raise healthy “winter bees.”
• Manage Late-Season Brood: Be aware that mites concentrate on the last rounds of seasonal brood production so be sure to monitor closely and plan accordingly.
• Avoid Reinfestation: Collapsing or untreated colonies nearby can cause mite spikes through robbing so use entrance reducers or screens as needed.

Winter

• Assess Winter Losses: Check dead-outs to determine if Varroa mite may have been a contributing factor (e.g., small cluster, adequate food remaining, visible signs of mite frass (i.e. fecal material) in cells, bees with visible mites on their bodies, bees with deformed wings).
• Clean Equipment: Remove and clean out dead colonies and equipment before reuse to reduce potential pest and disease carryover.
• Plan Ahead: Order mite-resistant queens or supplies early and review monitoring/treatment plans for the upcoming season.
• Minimize Disturbance: Avoid unnecessary hive openings to reduce stress on overwintering colonies.

Additional Considerations

• Combine Strategies: No single method is fully effective on its own so consider using multiple approaches together provides better results.
• Monitor Effectiveness: Pair these practices with regular sampling to understand how well they are working.
• Do Your Research: Additional tools and techniques may be available, but always evaluate methods carefully to ensure they are safe and appropriate for your apiary.

3. Monitoring Varroa Mites: Alcohol Wash Sampling

Regular monitoring is essential to effective Varroa mite management, as it provides the data needed to make informed treatment decisions. Sampling at least once per month is recommended, and the alcohol wash is widely considered the most accurate method for determining mite levels in your hives.

The following materials and 10-step process outline how to perform an alcohol wash to assess Varroa mite populations:

Materials Needed:

• Pint jar with solid and mesh lids (1/8" hardware cloth)
• 1/2 cup measure
• Dishpan (white or lightly colored for visibility)
• Rubbing alcohol (50-70%)

10-Step Process:

1. Pour rubbing alcohol into the jar, remove both lids and set aside within easy reach.
2. Select a frame with open brood (carefully ensure the queen is not on the frame).
3. Shake adult bees from the frame into a dishpan.
4. Scoop 1/2 cup of bees (~300 bees) into the jar.
5. Return the remaining bees from the dishpan back into the colony.
6. Secure the solid lid on the jar and shake vigorously for 1–2 minutes.
7. Let the jar sit upright for 1–2 minutes to allow mites to dislodge.
8. Replace the solid lid with the mesh lid.
9. Shake the contents of the jar upside down, draining the liquid and mites into the dishpan
10. Count the mites. If mite levels exceed threshold (e.g., more than 3 mites per 300 bees), treatment is recommended. Discard bees and mites, and clean materials. for future use.

4. Treating Varroa Mites: Intervene With Chemicals

Chemical treatments—classified as pesticides—play an important role in Varroa mite IPM when monitoring shows populations have reached damaging thresholds. When used correctly and at the appropriate time, these products can reduce mite levels and protect colony health. Remember: the label is the law—always follow the EPA-approved label for any product used. EPA labels can be found using the EPA Pesticide Product Label System.

Before applying any treatment, carefully read and follow the EPA-approved product label to ensure you are using the most current guidance on application methods, safety requirements, and the appropriate personal protective equipment (PPE). Pesticide product labels specify required PPE. At a minimum, this includes long sleeves, long pants, closed-toe shoes with socks, and chemical-resistant gloves; some products may also require protective eyewear or a respirator, so always check the specific label. Using proper PPE ensures both safety and compliance—refer to the EPA Pesticide Product Label System for the most up-to-date requirements.

A current list of all EPA-registered pesticide products approved for use again the Varroa mite can be found using the EPA-Registered Pesticide Products Approved for Use Against Varroa Mites in Bee Hives. The table below lists all Massachusetts registered pesticide products currently approved for use against Varroa mites in bee hives (updated March 2026). To maintain effectiveness and reduce the risk of resistance, rotate products and integrate chemical treatments with non-chemical practices as part of a comprehensive IPM strategy.

THE LABEL IS THE LAW: Always follow the EPA label for any product used.

Chemical Type	Product Name	EPA Registration Number	Active Ingredient	Mode of Action	Season	Temperature Range	Treatment Duration	Application Type	Honey Super Safe?
Synthetic	Apivar®, Apivar® 2.0	87243-1 and 87243-5	amitraz	contact	Spring, Fall	no temperature restriction	6-10 weeks	plastic strip	no
Synthetic	Amiflex® 2.0	87243-4	amitraz	contact	Spring, Fall	no temperature restriction	1 week	gel applicator	no
Synthetic	Checkmite+®	11556-138 and 1156-138-61671	coumaphos	contact	Spring, Summer, Fall	no temperature restriction	42-45 days	plastic strip	no
Synthetic	Apistan®	2724-406-62042 and 2724-406-79671	fluvalinate	contact	Spring, Summer, Fall	greater than 50°F	42-56 days	plastic strip	no
Essential Oil	Apiguard®	79671-1	thymol	fumigant	Spring, Fall	60-105°F	4-8 weeks	gel or gel tray	no
Essential Oil	Api Life Var®	73291-1	thymol, menthol, eucalyptus oil	fumigant	Spring, Fall	64-95°F	26-32 days	foam wafer	no
Organic Acid	Formic Pro®	75710-3	formic acid	fumigant	Spring, Summer, Fall	50-85°F	2-3 weeks	gel strip	yes
Organic Acid	Api-Bioxal®, Ez-Ox Tablets	73291-2 and 101743-2	oxalic acid dihydrate	contact, fumigant	Spring, Fall, Winter	no temperature restriction	immediate	power, tablet	yes
Organic Acid	Api-Bioxal RTU®	73291-3	oxalic acid dihydrate	contact	Spring, Fall, Winter	no temperature restriction	immediate	liquid dribble	yes
Organic Acid	Varroxsan®	94413-3	oxalic acid dihydrate	contact	Spring, Summer, Fall	no temperature restriction	6-8 weeks	fiber strip	yes
Organic Acid	HopGuard® III	83623-2	potassium salt of hops beta acids	contact	Spring, Summer, Fall	55-99°F	2-4 weeks	cardboard strip	yes
RNAi	Norroa®	94614-4 and 94614-5	vadescana	contact	Spring, Fall	no temperature restriction	2-6 weeks	liquid filled pouch	yes