Inheritance of Resistance to Acarapis woodi (Acari: Tarsonemidae) in Crosses Between Selected Resistant Russian and Selected Susceptible U.S. Honey Bees (Hymenoptera: Apidae)

Authors: Villa, Joseph; Rinderer, Thomas

Submitted to: Journal of Economic Entomology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 7/8/2008
Publication Date: 12/1/2008
Citation: Villa, J.D., Rinderer, T.E. 2008. Inheritance of Resistance to Acarapis woodi (Acari: Tarsonemidae) in Crosses Between Selected Resistant Russian and Selected Susceptible U.S. Honey Bees (Hymenoptera: Apidae). Journal of Economic Entomology 101(6):1756-1759(4).

Interpretive Summary: Tracheal mites can cause serious economic hardship for beekeepers especially in apiaries in colder climates. Many U. S. commercial sources of bees are highly susceptible and infestations can reach high levels even during summer months. Colonies surviving to the winter with moderate to high levels typically die. Bees imported from Russia are resistant to these mites and have been released to the beekeeping industry. We investigated the level of resistance of hybrids between resistant Russian bees and highly susceptible U.S. colonies in both short evaluations and by sampling colonies through a season. Russian bees transfer a useful level of resistance to hybrids. In some crosses resistance of hybrids was as good as the Russian population. In other crosses resistance was more intermediate. The use of pure or crossed Russian queens in beekeeping operations can greatly reduce or eliminate problems with tracheal mites.

Technical Abstract: The pattern of inheritance of tracheal mite resistance in selected Russian bees was determined in bioassays and in samples from Þeld colonies. Resistant colonies of Russian origin and colonies selected for high susceptibility in the United States were used to generate divergent parental populations. Seven groups of F1 colonies were produced by crossing queens and drones from these selected resistant Russian and selected susceptible populations. In a series of bioassays with young workers exposed in infested colonies, average mite abundance (female mites per worker) in F1 colonies was intermediate (1.04
0.13 [mean
SE]) and signiÞcantly different from that of both resistant Russian (0.74
0.13) and selected susceptible (1.57
0.13) colonies. Colonies representing the three populations were established in two apiaries in July 2005. Colonies surviving with original queens after 10 mo had mite prevalences supporting the Þndings of the bioassay. All three resistant colonies had undetectable mite levels, whereas prevalences in four F1 colonies ranged from 0 to 53%, and in 10 susceptible colonies ranged from 0 to 90%. Tracheal mite resistance in Russian bees is likely polygenic, but there may be a number of genes with major dominance interacting with minor genes. Use of selected Russian queens mated with Russian drones or with drones from unknown sources is beneÞcial for beekeeping in areas with persistent problems with tracheal mite infestation.