The Bee Bench › Varroa Mite Check
You counted the mites. Here's what the number actually means, and whether you're over the line for the time of year.
Take the sample from an open brood frame — that's where the mites are. Shake the bees off the frame into a tub first, then scoop. Make sure the queen isn't in there.
The colony figure counts only the mites riding on adult bees. When there's capped brood, roughly two out of three mites are hidden inside cells where no wash will find them — so the true load is often two to three times this.
| Time of year | Act at | Why |
|---|---|---|
| Spring build-up | 2 per 100 | Mites double roughly every month once brood rearing is going. A low spring count is what keeps August manageable. |
| Summer, peak population | 3 per 100 | Big colony, lots of brood. Still the point where virus load starts showing up in the bees. |
| August–September | 2 per 100 | The strictest window. These are the bees that have to live six months. Mite-damaged winter bees are why colonies die in February. |
| Broodless late fall | 1 per 100 | Every mite is exposed and countable. Also the single best time to hit them with oxalic acid. |
Thresholds follow the Honey Bee Health Coalition's Tools for Varroa Management. Sample every colony you can, not just the ones that look bad — the strongest hive in the yard is often the one robbing out a collapsing one down the road and picking up its mites.