APICULTURE AND SOCIAL INSECTS An Evaluation of the Associations of Parameters Related to the Fall of Varroa destructor (Acari: Varroidae) From Commercial Honey Bee (Hymenoptera: Apidae) Colonies as Tools for Selective Breeding for Mite Resistance

Varroa destructor (Anderson and Trueman) trapped on bottom boards were assessed as indirect measurements of colony mite population differences and potential indicators of mite resistance in commercial colonies of Russian and Italian honey bees (Apis mellifera L.) by using 35 candidate measurements. Measurements included numbers of damaged and nondamaged younger mites, nymphs, damaged and nondamaged older mites, fresh mites, and all mites, each as a proportion of total mites in the colonies and as a proportion of all trappedmites or all trapped freshmites. Several measurements differed strongly between the stocks, suggesting that the detailed characteristics of trapped mites may reßect the operation of resistance mechanisms in the Russian honey bees. Regression analyses were used to determine the relationships of these candidate measurements with thenumber ofmites in the colonies. The largest positive regressions differed for the two stocks (Italian honeybees: trappedmites and trappedyoungermites; Russian honeybees: trapped youngermites and trapped fresh mites). Also, the regressions for Italian honey bees were substantially stronger. The largest negative regressions with colony mites for both stocks were for the proportion of older mites out of all trapped mites. Although these regressions were statistically signiÞcant and consistent with those previously reported, they were weaker than those previously reported. The numbers of mites in the colonies were low, especially in the Russian honey bee colonies, which may have negatively inßuenced the precision of the regressions.