Tracheal mite


Three species mites in the genus Acarapis are specific to Apis mellifera: Acarapis woodi, A. dorsalis and A. externus.  The first one is an internal parasite colonizing the tracheae (Fig.1), the other are external parasites.

These agents are morphologically very similar and are differentiated mainly by their location in the bee host (Webster & Delaplane 2001).

Acarapis prefer to parasitize young bees so are subject to seasonal fluctuation according to the number of young bees (major in spring-summer than in autumn-winter). The life cycle of Acarapis is spent on a single adult bee, and the close contact between bees allows the female mites to parasitize other bees when the population of mites is too high or when the host is going to die. (Webster & Delaplane 2001).

Fig 1: Thracheal mite (Acarapis woody) inside a honey bee thtachea (USDA Agricultural Research Service (ARS)).

In common with the Varroa mite these are also blood feeders but owing to their smaller size symptomatology is usually milder.. For this reason beekeepers do not commonly treat this disease.  However Acarapsis spp. are also able to transfer viruses and treatment might therefore be beneficial. Certainly external Acarapis spp. areis sensitive to the common Varroa treatments, but Acarapis woodi could be protected by their internal localization (Webster & Delaplane 2001).

Follow the link to FERA -NBU website to know more about Tracheal mite or the chapter 2.2.1 of the O.I.E. Terrestrial manual (2008).