Bob Harrison wrote:
>The authors clearly state that A.m.m was originally on 5.0mm. cell in the
>late 1800's in England & Ireland. Then in the 1920's foundation of 5.5mm.
>was introduced.

It should be pointed out that it is Apis mellifera mellifera that they are
talking about and not Italians or Carniolans, from which most US commercial
strains are derived. These bees are larger.

> The brood-cell size of the Northern European dark bee, A. mellifera
mellifera, which was indigenous to Britain and Ireland up to the early part
of the twentieth century, was in the range of 4.9–5.1 mm (Cowan 1904;
brood-cell size was measured as the distance between the opposite faces of
the hexagonal cell). The period from the late 1800s to the 1920s saw a major
change in cell size with the introduction of commercially produced
foundation of about 5.5 mm width (Erickson 1990). Erickson suggested that
brood comb cell widths greater (or smaller) than normal might stress
colonies making them more susceptible to parasites.

> There was no evidence that the susceptibility to tracheal mite infestation
of bees raised in small-sized brood cells was any different to that of those
raised in standardsized brood cells and thus the hypothesis is rejected. The
female mite abundance and fecundity in bees from the two cell sizes were
similar. Hence, there is no reason to believe that the increase in cell size
in the late 1800s—early 1900s period influenced the onset of tracheal mite
infestation in the indigenous honey bee in Britain and Ireland, A. m. mellifera.

from 
Brood-cell size does not influence the susceptibility of honey bees (Apis
mellifera) to infestation by tracheal mites (Acarapis woodi) by John B.
McMullan Mark J. F. Brown

******************************************************
* Full guidelines for BEE-L posting are at:          *
* http://www.honeybeeworld.com/bee-l/guidelines.htm  *
******************************************************