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Varroa calculator
Enter your count; the infestation rate is calculated and compared with the threshold for the month. Thresholds are approximate values recommended by European bee institutes.
Half a cup (about 100 ml) of bees ≈ 300 bees
Thresholds by month
| Month | Mites per 100 bees: Moderate / High | Daily mite drop: Moderate / High |
|---|---|---|
| January | ≥ 1 / > 2 | ≥ 0.5 / > 1 |
| February | ≥ 1 / > 2 | ≥ 0.5 / > 1 |
| March | ≥ 1 / > 2 | ≥ 0.5 / > 3 |
| April | ≥ 1 / > 2 | ≥ 0.5 / > 3 |
| May | ≥ 1 / > 2 | ≥ 0.5 / > 3 |
| June | ≥ 2 / > 3 | ≥ 3 / > 10 |
| July | ≥ 2 / > 3 | ≥ 5 / > 10 |
| August | ≥ 2 / > 3 | ≥ 5 / > 10 |
| September | ≥ 2 / > 3 | ≥ 1 / > 5 |
| October | ≥ 2 / > 3 | ≥ 1 / > 5 |
| November | ≥ 1 / > 2 | ≥ 0.5 / > 1 |
| December | ≥ 1 / > 2 | ≥ 0.5 / > 1 |
The table shows the approximate points where moderate and high levels begin. Follow the advice of your local beekeeping institute for your region and hive type.
Frequently asked questions
How is the varroa infestation rate calculated?
Wash about 300 bees (half a cup) in alcohol or powdered sugar and count the mites that fall off. Mites ÷ bees × 100 gives the mites per 100 bees (percent infestation). Example: 9 mites in 300 bees = 3 per 100 bees.
How many varroa mites are dangerous?
In late summer and autumn more than 3 mites per 100 bees usually calls for treatment straight away; in spring even 1–2 is high because the mite population grows fast over the summer.
How do I do a sticky-board count?
Slide a greased or sticky board under the screened floor, count the mites that have fallen after 3–7 days and divide by the number of days. Outside treatment periods this gives the daily natural mite drop.
Can varroa be counted from a photo?
Yes. The BeesLike app counts visible mites on a photo of a frame or sticky board; confirm the result with a wash test before deciding on treatment.
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In the knowledge library
Varroa (Varroa destructor): Treatment and Symptoms Varroa Counting Tools: Types and Uses Beekeeping calendar (month by month) Count varroa from a photo
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