4.1.1. Debris examination
Hives must be equipped with a bottom board on which debris are collected. The board must be protected by a mesh to prevent bees from discarding the dead mites. The mesh size should allow the mites to fall through. To increase probability to detect mites, colonies can be treated with a varroacide. After a few days, dead mites can be observed on the boards. In case a large quantity debris prevents easy detection of mites, debris can be cleaned from the varroa board and examined using a flotation procedure:
1. Dry debris for 24 h.
2. Flood with industrial grade alcohol.
3. Stir continuously for 1 minute or up to 10-20 min if debris contain wax or propolis particles.
4. Investigate the surface of the alcohol for the presence of mites.