4.1.2. Brood examination
Since varroa mites prefer drone brood, the probability to detect them on male pupae is higher than on worker brood. However, in absence of drone brood worker brood is used. When a large number of samples are examined, a rough determination of the degree of infection can be obtained.
1. Remove the cappings of the brood cells with a knife or fork.
2. Flush the pupae out of the combs with a stream of warm water over a sieve (mesh width 2–3 mm).
3. Collect the mites in a second sieve (mesh width 1 mm) placed below the
4. Examine the contents of the second sieve on a bright plate, where the mites can be easily identified and counted.
When a smaller number of samples are examined,
1. Open individual cells.
2. Remove larva, pre-pupa or pupa.
3. Examine cell walls using an appropriate source of light.
4. Identify infected cells by the presence of small white spots – the faeces of
the mite (Fig. 3).
5. Confirm the presence of the mites themselves in the cell or on the brood.