One of the best ways to assess the infestation rate inside a hive is to manually uncap drone cells and extrapolate the numbers.
This simple yet effective method will give you valuable insights and will help you take action fast and when it’s needed.
Why Drone Cells?
Varroa mites prefer drone brood over worker brood because of the longer development time inside drone cells.
This extended period allows the mites more time to reproduce, making drone cells a hotspot for Varroa activity.
The Process of Uncapping Drone Cells
Uncapping drone cells is pretty straightforward:
Identify Drone Comb:
Drone cells are larger than worker cells, making them easy to spot.
They often appear in specific areas of the hive, particularly near the edges of the brood nest or in places where the beekeeper intentionally left the bees to build a comb without a frame.
Use an Uncapping Tool:
A sharp tool or knife can be used to gently open the caps of the drone cells.
This will expose the developing drones, where you can look for Varroa mites attached to them or you can remove the brood and check inside the cells.
Count the Mites:
Carefully count the number of mites you find on the drone pupae.
While it’s impossible to inspect every cell, examining a good sample size can provide a reliable estimate.
Extrapolating the Results
Once you’ve gathered a sample of drone cells, you can use the data to estimate the overall infestation rate in the hive.
The more mites you find in the drone cells, the higher the likely infestation across the colony.
For example, if you find several mites in a handful of drone cells, it’s a strong indicator that the Varroa population is rising, and treatments may be needed yesterday.
On the other hand, if you find very few or no mites, your colony is likely in good shape.
Why This Method Works
Uncapping drone cells is an effective way to gauge Varroa levels because it provides direct evidence of infestation.
Unlike sticky boards or alcohol washes, which estimate mite fall or population, uncapping drone cells lets you see exactly where the mites are reproducing.
This method is especially useful in early spring and late summer when drone brood is abundant.
Catching Varroa infestations at these times gives you a chance to take action before the mites become a significant threat to the hive and before winter kicks in.
