>Anyone has further information on those or any others?

I communicated with Dr. Tammy Horn Potter, State Apiarist for Kentucky and
she offered the following (with permission to share):

*'A few years ago (2017 or 2018, can't remember which), the Tennessee State
Apiarist Mike Studer had done some microscopy of bees from commercial
beekeepers and found high levels of tracheal mites.  Many of the beekeepers
had only used oxalic acid as a treatment, and typically were using the
oxalic acid in a method not consistent with the label directions (i.e.,
winter or when there is no brood in the hive).  *

*To my knowledge, there were no microscopies of honey bees in KY showing
high levels of tracheal mites.  However, since I stressed many times in the
Beelines *[our state Honey Bee Association newsletter] *to use many types
of treatments, perhaps beekeepers took that advice.  Apiguard in particular
has the added advantage of not only treating varroa mites but also treating
for tracheal mites too.'  *

I have contacted Mr. Studer and will report back to the list should I learn
any further details concerning his microscopy results.

             ***********************************************
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