Skip to content

Varroa Treatment Calculator

Calculate varroa mite treatment dosage from colony size and treatment method. Apply oxalic acid, formic acid, and apivar at correct rates.

Use this result well

Inputs that matter
Hive Size, Treatment Type, Mite Count (per 100 bees)
Output to expect
Varroa Treatment Calculator
  • Check the units and required inputs before comparing results.
  • Keep the assumptions with a copied result so you can reproduce the calculation later.
Was this tool helpful?

Related Tools

Tools you might need next

Varroa Mite Threshold Calculator

Determine if Varroa mite count exceeds treatment threshold. Free online beekeeping calculator with instant, accurate results.

Beekeeping
Varroa Mite Calculator

Calculate varroa mite infestation level from alcohol wash or sticky board counts. Free varroa mite calculator for treatment thresholds and hive health.

Beekeeping
Heat Treatment RI Shift

Estimate refractive index shift indicating possible heat treatment in corundum. Free heat treatment indicator tool for heat, treatment, and more.

Gemology

Reference & details

How it works

Treatment Threshold

Treat when mite levels exceed 2–3% in spring (3 mites per 100 bees alcohol wash) or 3% in fall (before winter bee production). Delay risks virus transmission.

Mite % = (mites counted / ~300 bees sampled) × 100

Oxalic Acid Vaporization

Standard dose: 1 g oxalic acid dihydrate per brood box (deep). Apply with vaporizer when little or no brood present (late fall/winter) for maximum efficacy.

OA dose (g) = number of brood boxes × 1 g

Formic Pro / Apivar Dosing

Formic Pro: 2 strips per brood box for 14 days (double deep = 4 strips). Apivar: 2 strips per brood box for 42–56 days. Follow product label exactly.

Strips = brood boxes × 2 strips per box

Updated: July 2026

Example Scenarios

After broodless period in November: 2 g OA dihydrate total (1 g per box). Treat 3 times at 5-day intervals for 90%+ mite knockdown on phoretic mites.

5/300 = 1.7% — below 3% spring threshold. Monitor monthly; treat if rising before honey flow if using mite-tolerant approach, or treat proactively per your IPM plan.

One brood box: 2 Apivar strips hung between brood frames for 42 days minimum. Do not harvest honey during treatment; remove strips after period per label.

Common Mistakes to Avoid

Treating oxalic acid when brood is present without extended protocol

OA vaporization kills phoretic mites only — 80%+ mites are in brood cells during spring/summer. Treat broodless periods or use brood-active treatments (formic, Apivar, thymol).

Under-dosing Apivar or leaving strips too short a time

Apivar requires 42–56 days contact and 2 strips per box. Under-dosing breeds mite resistance and fails to control population. Follow label duration exactly.

FAQ

Treat when alcohol wash exceeds 3 mites per 100 bees (3%) in fall, or 2–3% in spring. Always treat in fall regardless of count to protect winter bees from DWV.

Vaporization: 1 g oxalic acid dihydrate per brood chamber. Dribble method: 5 ml of 3.2% solution per seam of bees (follow exact formula — overdose kills bees).

Most treatments are not label-approved during honey supers on. Formic acid can be used with supers removed or per label timing. Plan treatments for post-harvest or pre-super spring.

Alcohol wash or powdered sugar roll: collect ~300 bees from brood frame (half cup), count dislodged mites. Alcohol wash kills sample; sugar roll returns bees.

Fall mites reproduce on winter bee brood, vectoring deformed wing virus. Winter bees must be healthy — fall treatment protects the long-lived winter generation.

About Varroa Treatment Calculator

Varroa destructor mites require treatment at threshold levels to prevent colony collapse. This calculator determines correct treatment dosage based on colony size, treatment product, and application method per label and research guidelines.