> In retrospect, it appears that the U.S. honey bee population contained some alleles that conferred resistance to tracheal mite, and that natural selection greatly reduced the prevalence of alleles that did not confer resistance. This would result in "herd immunity" against the mite.
I recall that on the early 1990's when Australia was exporting queen bees to Canada some were being tested for tracheal mite resistance by a program at Guelph and it was found that many were resistant.
As we do not have tracheal mites in Australia we cannot test for resistance here.
Trevor Weatherhead
Australia
***********************************************
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