Re: Puzzling varroa numbers
Mites enter and leave brood cells every day. How many are groomed off or simply fall depends on the numbers that are on the bees versus in the cells. That is why a three to seven day count is better than just one day, you will get an average that is more accurate than just one day.
Most of the literature now recommends the 300 bees in a jar sample, but that will depend on which frame you get the sample from. It is best to take the sample from the brood nest, and to always take the sample from the same frame. This gives a consistent chance that the numbers are accurate.
40 years - 25 colonies, 32 Nucs - IPM disciple - Naturally Skeptic