Submitted to: Journal of Economic Entomology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 2/1/2014
Publication Date: 4/10/2014
Citation: Rinderer, T.E., De Guzman, L.I., Frake, A.M., Tarver, M.R., Khongphinitbunjong, K. 2014. 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. Journal of Economic Entomology. 107(2):516-522. Interpretive Summary: Widespread breeding of honey bees for resistance to the highly destructive parasitic mite, Varroa, requires a simple and rapid measurement tool. Prior work by scientists at the ARS Honey Bee Breeding and Genetics Unit in Baton Rouge suggested that increased proportions of older mites among fallen mites collected from bottom board traps related well to reduced numbers of mites in colonies and that the proportion of younger mites among fallen mites related will to absolute numbers of colony mites. This study evaluated these measurements for commercial colonies of Italian honey bees in California and colonies of Russian honey bees in Arkansas. Although the total numbers of mites in these colonies were fewer than in the previous study, the proportions of older mites and younger mites differed strongly between the two stocks as did the total number of mites in colonies. The relationships of the proportions to colony mites were statistically significant and consistent with those previously reported. However, the relationships were weaker in this study owing to the overall lower number of mites. Further refinements of this measurement system is required for use by commercial honey bee breeders.
Technical Abstract: Varroa destructor (Anderson and Trueman) trapped on bottom boards were assessed as indirect measurements of colony mite population differences in commercial colonies of Russian and Italian honey bees (Apis mellifera L.) using 35 candidate measurements. Measurements included numbers of damaged and non-damaged younger mites, nymphs, damaged and non-damaged older mites, fresh mites and all mites, each as a proportion of total mites in the colonies and as a proportion of all trapped mites or all trapped fresh mites. Several measurements differed strongly between the stocks, suggesting that the detailed characteristics of trapped mites may reflect the operation of resistance mechanisms in the Russian honey bees. Regression analyses were used to determine the relationships of these candidate measurements to the number of mites in the colonies. The largest positive regressions differed for the two stocks (Italian honey bees: trapped mites and trapped younger mites, Russian honey bees: trapped younger mites 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. While these regressions were statistically significant 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 influenced the precision of the regressions.