In message <[log in to unmask]>, Joe Hemmens
<[log in to unmask]> writes
>
>The research undertaken by Dr. Martin is interesting and no
>doubt adds to the knowledge base.  As a paid-up member of
>the cynics-club I suspect that the Varroa Calculator was a
>way of justifying the cost of the research (paid for by beekeepers in
>the UK).
>
>I also believe that the Varroa Calculator has no practical
>use for the beekeeper whatsoever.

>Either of these two factors alone would suggest that the
>Varroa Calculator is well nigh useless.
>Joe Hemmens


These are strong condemnations of one of the very few pieces of research
work carried out recently  by MAFF in the UK intended to be of practical
use to small scale beekeepers.  In view of the strength of the views
expressed it would be valuable to the beekeeping community for all the
relevant data to be in the public domain, and for the accuracy of the
technique to be discussed on the basis of these data.

The data that are published on the Internet on the DARG trial are headed
"Apilife VAR trial Results-Autumn 1996", obtained from

http://www.geocities.com/CapeCanaveral/Lab/2352/

I just checked and they are still there.  Are there any other results
available to add to these?  I know that there was an article in the
Devon Beekeepers Magazine after the trial.  Did it contain any
additional information.

These results of the DARG trial refer to 36 colonies using no less than
6 different designs/arrangements of hive; it seems a bit hard on Dr
Martin to criticise him for using " no more than 30-40 colonies".

The publised DARG data do not define the treatment period other than as
"during the Autumn of 1996".  If it is assumed assume that the natural
mortality drop counts were made in Late August/September, as "autumn"
would imply in the UK, then the Varroa calculator states that during
this time "...multiplication factors for daily mite fall are unreliable.
A rough estimate is given below to be used only for guidance".  A factor
0f 100 times the daily might drop is then quoted for September and
October.

If this factor is used on the DARG results, then, with the exception of
two results both with measured mite drop rates of less than 1 per day,
the ratios of the total measured mite population (taken to be the sum of
all the drops measured during the trial) to the prediction of the Varroa
calculator are in the range 0.4 to 8.2;  this might well be regarded as
"a rough estimate"

For colonies in the DARG trial with natural drop rates of 3  or more per
day ( and this includes 23 of the 36 trial colonies) the ratios of
measured total to estimated lie in the range 0.4 to 3.3.  Approximately
half the ratio results in this case lie in the range 0.5 to 2; this
looks like quite a reasonable guide.

In any case, one of the benefits of the natural drop count and the use
of the varroa calculator is the ability to estimate the build up of
varroa mites in a colony through the summer season so that treatment can
be given if a dangerous build up occurs, as can sometimes happen quickly
if local, untreated, colonies start to collapse and their bees fly to
other local colonies.  The DARG results do not appear to be relevant to
the accuracy of the Varroa Calculator during the summer period.

"the Varroa Calculator has no practical
use for the beekeeper whatsoever" and "the Varroa Calculator is well
nigh useless"- Of such strong statements are myths and legends made!!

The varroa calculator is less than perfect, but this warning is made
clear on the device.  If we are going to condemn it, let us at least do
so on the basis of all the data, and with a full analysis of them.

Regards
--
Mike Rowbottom


HARROGATE
North Yorkshire
HG1 2PY