Field evaluation of nine families of honey bees for resistance to tracheal mites

We evaluated the resistance to tracheal mites, Acarapis woodi (Rennie) (Acari: Tarsonemidae), of colonies of honey bees, Apis mellifera L. (Hymenoptera: Apidae), headed by daughters of three queens from each of three honey bee stocks: (i) British Columbia "mite-resistant" stock, (ii) Buckfast "mite-resistant" stock, and (iii) Canadian unselected stock. Colonies of all nine families were distributed among four apiaries; half of the colonies in each apiary were treated with formic acid to attempt to control tracheal mites. The study documented significant differences in resistance to tracheal mites among the families of bees, even within each of the three stocks. After the First 4 months of study (by November 1993), differences in mite infestations had developed among the nine families. Formic acid treatments had either short-lived effectiveness (1993) or no effect (1994) on tracheal mite infestations, thereby eliminating the opportunity to evaluate colony performance in the absence of mites. Mite infestations varied significantly among apiary sites. This study highlights the value of evaluating sets of colonies headed by sister queens when identifying mite-resistant stock for breeding purposes.