> beekeepers will treat their newly hived packages with either HopGuard II or oxalic acid, retreating in the Fall, and checked monthly for efficacy of treatments. This monitored trial is a first for the Northeast region. 

Field trials using beekeepers as guinea pigs: bear in mind that these treatments may 1) do nothing to control mites -- which wastes precious time you could use applying something that's proven; 2) actually harm your colonies. I would recommend staying away from field trials. Let the sponsors try them on hives they purchased. I participated in a field trial last year with a formula that did nothing. It gives you a sense that you are "doing something for the bees" when you aren't. 

By the way, treating spring and fall misses the point: mite levels are highest in late summer due to mite invasion. 

¶

VARROA MITE POPULATION GROWTH: A factor that might contribute to the growth of Varroa populations is the migration of mites into colonies on foragers from other hives. Clarence Collison  http://www.beeculture.com/clarence-collison-closer-look/

Population growth of Varroa destructor (Acari: Varroidae) in honey bee colonies is affected by the number of foragers with mites. DeGrandi-Hoffman, G., F. Ahumada, V. Zazueta, M. Chambers, G. Hidalgo and E.W. deJong  2016.   Exp. Appl. Acarol.

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