>nowadays it is very rarely mentioned.

Maybe because:

'It was later shown that the tracheal mite was not the cause of the "Isle of Wight" disease (Bailey 1964), and later reports (Bailey 1968, Morse 1978) indicate that Acarapis woodi is not as serious a pest of honey bees as previously thought. In combination with other adverse conditions, however, heavy mite infestations may cause a reduction in bee activity.'

http://entnemdept.ufl.edu/creatures/misc/bees/tracheal_mite.htm

             ***********************************************
The BEE-L mailing list is powered by L-Soft's renowned
LISTSERV(R) list management software.  For more information, go to:
http://www.lsoft.com/LISTSERV-powered.html