Submitted to: Mites of the Honey Bee
Publication Type: Book / Chapter
Publication Acceptance Date: January 7, 1999
Publication Date: N/A
Interpretive Summary: Some types of honey bees have been found to be resistant to tracheal mites. These mites are internal parasites that have been associated with the deaths of large numbers of colonies in North America during the past 14 years. This book chapter reviews what has been learned about genetically based resistance of bees to the mites. Beekeeping history from this century suggested that mite resistance does exist and can be used to solve mite problems. Recent scientific research has upheld this assertion and added details about resistance. Resistant bees can effectively remove tracheal mites off themselves by grooming. Resistant bees pass the trait to their offspring. Breeders of honey bees can therefore enhance resistance in stocks by hybridizing with existing resistant bees. Alternatively,a simple selection procedure can be used to enhance resistance in a bee breeding program. In this case, young worker bees are obtained from colonies of interest and are screened for resistance by exposing them to tracheal mites in infested colonies. The resultant mite infestations are compared in the workers from different test colonies,and breeder colonies are selected based on workers having low infestation.
Technical Abstract: Some honey bees have a genetically based resistance to parasitic tracheal mites, Acarapis woodi. Resistance was reputed to have arisen in some managed bees soon after tracheal mites became a beekeeping problem in the United Kingdom in the early 1900's. There was no scientific corroboration of these reports from beekeepers until the 1990's, soon long after tracheal mites began devastating bees in North America. Recent research has shown that the main mechanism regulating resistance is the ability of worker bees to groom mites off themselves and thus interrupt the transfer of female mites between host bees. Resistance is now known to be heritable, and bee breeders can effectively incorporate the trait of resistance into new stocks by hybridizing with existing resistant bees. In addition, bee breeders can use a simple protocol to select for more resistant colonies from among their own bees. Young (<24 hours old) adult worker bees from potential breeder colonies are marked to identify colony source, added to inoculation colonies having a moderate mite infestation (about 25-75% of workers infested), retrieved after 4-7 days, and dissected to determine levels of mite infestation. Colonies having workers with low infestation are selected as breeders for the next generation.