A frame divided vertically into thirds is placed in the center of the brood nest. The bees build drone comb on it. A third of the frame is removed every 8 days with capped drone brood. With the brood goes a good number of mites. The drone brood thus becomes a magnet attracting Varroa which prefers drones because of their longer development time.
Preliminary results are encouraging, resulting in a reduction in overall infestation.
This technique was pioneered by a beekeeper in the area and shows that cooperation between beekeepers and scientists is close in northern Italy. Other research in Turin consists of toxicity tests on bees for a wide variety of pesticides. Substances are tested for their toxicity by both both contact and ingestion. Unfortunately, the testing procedure is different than that practiced in the U.S. and elsewhere in Europe. This makes the results incompatible.