>In article <001f01c254a7$091a8600$31b8193e@oemcomputer>, Peter Edwards
><[log in to unmask]> writes
>>Is this correct?  If so, what is the explanation for bald brood before we
>>had varroa?
>>
>>Peter Edwards
>>[log in to unmask]

Further to this thread, regarding the chewing out phenomenon, today I
had a chance, and a bit of time to spare, to investigate this further.

An apiary of 42 colonies on the heather was being stripped today, and
this involved some rearrangement of combs due to the presence of some
patches of brood in the upper boxes (an early Sept. phenomenon which
does not happen after another week or so).

This apiary is known to have a light infestation, treated in the spring,
but of course still present and growing again. Some chewing out was
noticed in most colonies (which would be normal) but markedly more in
around 6 of the group. I decided to investigate further and spend a
couple of hours excavating both chewed and unchewed brood in 3 of these
colonies.

In about 25% of the cells being chewed out in the first colony there was
either varroa present, or it faeces were visible on the cell roof.
Overall chewing out rate was less than 1% of the total sealed brood. I
then opened 25 cells of mature sealed brood. 8 of the 25 had varroa
present.

In the second colony probably about 1% was being chewed out. Nil varroa
activity noted in any of the cells. 25 cells then excavated of mature
brood and nil varroa found.

In the third colony again about 1% chewed and in this case about half of
the chewed cells showed evidence of varroa. As this was a higher figure
I excavated 100 cells and found varroa in 42. This colony also had more
varroa per cell where there was infestation.

Despite this I am not too fazed by this count, as the amount of brood in
total is now down to around four 'palm of the hand' sized patches and
thus very concentrated into a small area. No deformed wings or
undersized bees visible.

However, chewing does seem to be a pattern of behaviour which has little
correlation to varroa cleansing IN OUR ENVIRONMENT and with our bees.
A very scanty test to be jumping to conclusions on the basis of I know,
but for our circumstances it is all I can offer.


--
Murray McGregor