Hi Alan & all

> Internal cell size can't easily be determined from cell pitch due to
> variations in wall thickness (with age?)

I have done a good deal of rather fiddly measurements myself, and have found
wall thickness extremely difficult to measure with good repeatability.

One of the problems is whereabouts in the cell length that you take the
measurement, because the cell rims cause a sort of bottle necking that is
much deeper than most imagine.

There is a drawing taken from a 'plaster of paris' plug on a piece of Chris
Slade's comb...
http://website.lineone.net/~dave.cushman/chriscomb.html
This comb had not been bred in for many cycles and shows bottle neck shape
for aboout 15% of cell depth. The older the comb gets the more enhanced this
bottle neck gets and the depth to which extra wall thickening occurs
increases, so you have to remove this to get a 'true reading'.

Some really old cells do not exhibit this long thick neck and I reckon this
to be due to the cells being torn down and re-built.

> (I had been told that wall thicknesses were less than 0.1mm (0.004").(my
> meathod of measuring wall was to close the calipers gently until it
> gripped the wall)

I think that your calipers are gripping the thicker portions only, and that
if you remove a little more of the rim you will find the figures drop to
around 0.1mm (0.004").

I have found that the cell wall thickness at a position about 50% of cell
depth, hardly ever changes. I believe this is because the cocoon may be more
easily removed from the cell wall at this point, but I have no suggestions
as to why this would be the case.

It is good to see that someone else, will take the time and trouble to do
this sort of tedious work :-)


Best Regards & 73s, Dave Cushman... G8MZY
Beekeeping & Bee Breeding Website
Email: [log in to unmask] or  [log in to unmask]
http://website.lineone.net/~dave.cushman & http://www.dave-cushman.net

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