A comparative evaluation of sampling methods for Varroa destructor (Acari: Varroidae) population estimation

Obtaining a precise estimation of Varroa destructor population size in honeybee colonies is an important tool to implement integrated control practices. Therefore, it is necessary to know the adequacy and accuracy of the sampling methods used. We studied three sampling methods simultaneously to estimate the size of mite population: killing the mites with an acaricide, estimating the infestation level in adult bees and brood cells, and sampling the natural mortality of the mite. The three methods were compared pairwise by regression analysis. A good linear relationship was found between the three methods. Sampling the natural mortality was a reliable method for estimating absolute population size as long as some conditions are satisfied (colonies must be broodright and not collapsing). A mathematical equation is determined to translate the mite's natural death rate into absolute population numbers.