Studies of the honey bee tracheal mite (Acarapis woodi) (Acari: Tarsonemidae) during winter

Abstract

Changes in the populations of tracheal mites (Acarapis woodi) in individual honey bees were quantified in New York during winter. Mite prevalence increased greatly from November to February, then declined again in late spring. The simultaneous increases in prevalence values and in slight infestations restricted to the outer portions of the tracheae strongly suggest that many older bees were becoming infested with mites during the winter period when no brood was being reared. Trends in mite infestations varied greatly in different colonies for reasons that are not clear. Although mite reproduction was generally low (< 2.5 immatures per female), it appeared to be higher in October than during the rest of the winter. The sex ratio (3.04) was biased in favour of females. These patterns are different in some respects from those described for the same organism in Europe, emphasizing the need to carefully evaluate the biology of tracheal mites in North America and their interactions with their bee hosts before predicting their economic impact.