Submitted to: Apidologie
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: November 9, 2004
Publication Date: October 1, 2005
Citation: Danka, R.G., Villa, J.D. 2005. An association in honey bees between autogrooming and the presence of migrating tracheal mites. Apidologie 36(3)331-333. Interpretive Summary: Tracheal mites are parasites of honey bees which can damage or kill colonies when infestations involve a large portion of the worker bees. Some genetic strains of bees resist infestation by the mites. Indirect evidence has shown resistance is based chiefly on the ability of individual bees to effectively groom mites off themselves as mites are moving from bee to bee. In this study we observed bees of a colony in an observation hive (with transparent walls). We caught individual bees that had just begun to groom, anaesthetized them, and examined them for the presence of mites. We also caught bees that were not grooming and examined them for mites. Mites were discovered at a four-fold greater frequency on bees that had started to groom (36/50) than on non-grooming bees (9/50). For all cases in which we observed bees to groom only one side of their body we found a mite on that side. The results add to the evidence of an association between self-grooming in honey bees and the presence of tracheal mites.
Technical Abstract: Autogrooming has been suggested as a mechanism used by honey bees to resist infestation by tracheal mites. Bees are thought to groom chiefly by using the mesothoracic legs to remove migrating female mites from the thorax before the parasites enter the prothoracic spiracles. Bees in a highly infested colony (with mite prevalence ca. 90%) in an observation hive were scanned until a bee was seen to apparently initiate autogrooming. The bee was captured, narcotized in carbon dioxide, and examined under magnification for the presence of mites on the thorax. A second bee which was not grooming was collected from the same area of the hive and similarly examined. In all 50 such pairs of bees were used. There was a strong association between the initiation of autogrooming and the presence of tracheal mites. Mites were found at a 4-fold greater frequency on the thoraxes of grooming bees (72% with mites) than on non-grooming bees (18% with mites). Mites were found most commonly on the metatergum, propodeum and wing bases. Moreover, in all 34 cases in which a bee was seen to groom on just one side, a mite was found on the side being groomed. These observations support the hypothesis of a positive link between the presence of tracheal mites and autogrooming.