Varroa destructor mites are the number one killer of managed honeybee colonies worldwide. If you keep bees, you will deal with varroa. There is no "if" — only "when" and "how." This guide covers everything a beginner needs to know about identifying, monitoring, and treating varroa mites.
What Are Varroa Mites?
Varroa mites are tiny parasites (about the size of a pinhead) that attach to honeybees and feed on their fat bodies. They're reddish-brown, oval-shaped, and visible to the naked eye once you know what to look for. They reproduce inside capped brood cells, which means their population explodes as your colony grows through spring and summer.
Left untreated, varroa mites will:
- Weaken individual bees, shortening their lifespan by up to 50%
- Transmit deadly viruses (Deformed Wing Virus is the most common)
- Collapse your colony — usually within 1-2 years
- Spread to neighboring colonies through drifting and robbing
The bottom line: Treatment-free beekeeping is a goal some aspire to, but for beginners, treating for varroa is non-negotiable. You can explore treatment-free approaches after you have several years of experience and locally adapted stock.
How to Monitor: Know Your Mite Levels
You can't manage what you don't measure. Regular mite counts tell you when your colony needs treatment and whether your treatment worked.
The Alcohol Wash (Most Accurate)
- Scoop approximately 300 bees (about half a cup) from a brood frame into a jar with 70% rubbing alcohol
- Shake vigorously for 60 seconds
- Strain the liquid through a mesh — mites will separate from the bees
- Count the mites
Threshold: More than 3 mites per 100 bees (9 mites from a 300-bee sample) means you need to treat.
An Apivar + Varroa Easy Check bundle gives you both the monitoring tool and treatment strips in one purchase — a smart buy for beginners.
The Sugar Roll (Non-Lethal Alternative)
- Scoop 300 bees into a jar with a mesh lid
- Add 2 tablespoons of powdered sugar through the mesh
- Roll gently for 1-2 minutes
- Shake the sugar (and dislodged mites) out through the mesh onto a white surface
- Count the mites
The sugar roll is slightly less accurate than the alcohol wash but doesn't kill the bees. Use the same threshold: 3 mites per 100 bees.
When to Test
- Spring (April): Baseline count after winter
- Mid-summer (July): Before mite populations peak
- Late summer (August): Before or right after treatment
- Fall (September-October): Verify treatment worked
Treatment Options
There are several effective varroa treatments. Here are the most common ones for beginners, ranked by ease of use.
1. Apivar Strips (Amitraz) — Best for Beginners
Apivar strips are plastic strips infused with amitraz that you hang between brood frames. The bees walk over them, picking up the active ingredient which kills mites on contact.
- Efficacy: 97-99%
- Treatment time: 6-8 weeks (42-56 days)
- Temperature restrictions: None — works in any temperature when bees are active
- When to use: Spring or late summer/fall, after honey supers are removed
- Pros: Extremely effective, easy to apply, no mixing or special equipment needed
- Cons: Cannot be used during honey flow (with supers on), synthetic chemical
How to apply: Hang 2 strips per brood box, spaced 2 frames apart in the brood nest. Leave for 42 days minimum. Remove after 56 days maximum.
2. Oxalic Acid Strips — Organic Option
Varroxsan oxalic acid strips are a newer, slow-release organic treatment option. They use oxalic acid dihydrate in a cardboard matrix that releases the active ingredient over time.
- Efficacy: Up to 98.6%
- Treatment time: Varies — follow label directions
- Temperature restrictions: Works year-round
- When to use: Most effective during broodless periods (late fall/winter) or as a supplemental treatment
- Pros: Organic/naturally occurring compound, safe for bees, brood, and queens
- Cons: Newer product, less long-term data than Apivar
3. Formic Acid (Formic Pro / MAQS)
- Efficacy: 85-95%
- Pros: Kills mites under capped brood cells (the only common treatment that does this), can be used with honey supers on
- Cons: Temperature-sensitive (must be 50-85°F), can cause queen loss in some cases, strong fumes
- Best for: Mid-summer treatment when you can't pull supers
4. Thymol (Apiguard / ApiLife Var)
- Efficacy: 85-95%
- Pros: Natural essential oil, relatively easy to apply
- Cons: Temperature-dependent (above 60°F), bees may remove it, can taint honey flavor if supers are on
- Best for: Fall treatment in moderate climates
Treatment Calendar
| When | Action | Recommended Treatment |
|---|---|---|
| April | Baseline mite count | Test only — treat if above threshold |
| July | Mid-season mite count | Formic acid if supers are on; otherwise wait until August |
| August | Primary treatment (after harvest) | Apivar strips — the most reliable choice |
| October | Follow-up mite count | Verify treatment worked; re-treat if needed |
| December | Winter treatment (optional) | Oxalic acid strips during broodless period |
Signs Your Colony Has a Mite Problem
Don't wait for visible symptoms — by the time you see these, the infestation is severe:
- Deformed wing virus: Bees with crumpled, stunted wings crawling at the hive entrance
- Spotty brood pattern: Missing or dead brood scattered across the frame
- Parasitic mite syndrome (PMS): A combination of low population, spotty brood, and bees with shortened abdomens
- Visible mites: Reddish-brown dots on bees, especially on drone pupae
- Colony dwindling: Rapid population decline in late summer or fall
Common Mistakes
- Not treating at all. "My bees look fine" is not a mite management strategy. Mite populations are invisible until they're catastrophic.
- Treating too late. August treatment protects the winter bees your colony needs to survive. Treating in October is often too late — the damage is already done.
- Not doing follow-up counts. Always verify your treatment worked. If mite levels are still high, re-treat with a different product.
- Using powdered sugar as a treatment. Powdered sugar dusting is a monitoring tool, not an effective treatment. It does not reduce mite levels enough to save a colony.
Track Your Mite Counts
Recording your mite counts alongside your inspection notes helps you spot trends and time your treatments perfectly. Use Beekeeping Central's free hive tracker to log varroa counts with every inspection.
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