Submitted to: Journal of Apicultural Research
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 3/23/2006
Publication Date: 6/1/2006
Citation: Villa, J.D. 2006. Autogrooming and bee age influence the migration of tracheal mites to russian and susceptible workers. Journal of Apicultural Research 45(2):28-31 Interpretive Summary: Honey bees were imported to the United States from the Russian Far East primarily for their resistance to the highly destructive parasitic varroa mite. Among other additional useful characteristics, Russian bees have proven to be highly resistant to another parasite, the tracheal mite. In a number of field tests, Russian colonies have maintained the levels of these mites below harmful levels, even in northern climates where these mites tend to be most destructive. Earlier experiments had shown that strains genetically resistant to these mites were able to control them through removal of adult female tracheal mites with movements of the second pair of legs (self-grooming). Until recently, it was not known whether Russian bees have similar defensive mechanisms. Experiments were conducted by gluing together the second pair of legs of Russian and of highly susceptible workers, to compare the importance of self-grooming in bees of various ages. It is now clear that Russian bees can prevent a large proportion of mites from moving into their tracheae by using their second pair of legs for self-grooming, particularly in the first two days in the life of a worker.
Technical Abstract: The role of autogrooming in controlling tracheal mites in Russian and susceptible colonies was evaluated by gluing together the midlegs of workers and exposing them to mite infestation. In one experiment, young workers (less than 10 h old) from both strains having midlegs glued together at the tarsi (G) and left unglued as controls (C), were introduced into colonies with 50 to 75% of workers infested, and retrieved after five or six days. G Russian and susceptible workers had very high mite abundances (8.2 and 7.9 female mites/worker). However, C workers had significantly lower infestations, and strains differed significantly (Russian = 1.5 vs Susceptible = 3.0 female mites/worker). In a second experiment, C and G workers of both strains and from age classes produced every 24 h (1, 2, 3, and 4 d-old), were simultaneously introduced into an infested colony. Infestation of bees declined significantly in older bees and differences due to treatment and strain became less marked with increasing age of bees. The majority of mites infested the tracheae of workers less than 48 h old. The autogrooming efficacy of Russian workers during this critical period of 48 hours of high potential for mite migration appears to explain the resistance of their colonies to tracheal mites.