Just stumbles across this in searching for more info an cell size and
AHB. It is from

http://entomology.ucdavis.edu/faculty/mussen/7-8-97.html

Quote
Eric reported that local bees, living in combs with smaller cell sizes,
have survived the onslaught of Varroa and have less than
10% infestation rates. Tracheal mites are very low, too. They are hoping
to breed from those queens for mite resistance.
[Editor's Note: The AHBs in the USDA yard were living in previously
drawn EHB combs. Their mite level in uncapped drone
brood was about 50%.]
Unquote

What keyed my interest was the comment on increased varroa in EHB combs.
Along with another comment in the article:

Quote
Dr. Danka suggested that four traits might be of importance in Varroa
mite resistance: 1. decreased length of capped stage, 2.
grooming and biting mites, 3. hygienic behavior (removing infested
brood), and 4. failure of mites to reproduce in host cells.
Actually, the fourth trait is the most influential in these studies.
Unquote

I just wonder if the two are interrelated- cell size and failure of
mites
to reproduce in host cells. There is a tantalizing inference in the fact
that the AHB they were testing had high Varroa count on EHB comb which
would seem to discount the first three, since nothing has changed about
the bee, only the cell size. I wonder if when SMR is found it correlates
to the bees cell building. As size goes down, SMR increases?

Probably no correlation, but it is intriguing.

Bill Truesdell
Bath, ME