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Date: | Tue, 31 Jan 2006 10:59:36 +0000 |
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Hi all
I have had an offlist message from Olda that asked about the degree of
investigation...
As I think the reply is relevant to the thread on identification of AHB,
I copy my reply below...
****
Hi Olda
> How many parameters on the wing you measured? One? Two? Even if CI
> AND DS are correct, it doesn't guarantie that the bee is mellifera
> mellifera.
I fully agree, at various times I have used a number of different
parameters. The degree of investigation in any one case depends on the
amount of information you already know about the subject colony.
If you are looking at a colony from a breeding program, with a known
pedigree, it is possible to use smaller sample numbers and fewer criteria.
If the subject colony's history is totally unknown, you have to put in
more effort to get sensible conclusions.
> The only safe morphometry method is DAWINO.
I don't believe any morphometry method is totally 'safe' and should
never be relied upon without correlation with behaviour and/or DNA, but
in general the more work that is put in to collect the data the more you
can rely on the results that the data shows.
However some DNA studies conducted about 3 years ago, concluded that
only three colonies contained Italian genes out of 370 that were
previously thought to be AMM by behaviour and morphometry.
So a combination of DNA behaviour and morphometry can give sound
conclusions and behaviour and morphometry on their own can give results
of 0.0081% errors.
This information has to be tempered by the fact that we only have a test
that can definitely identify Ligustica genes, there may have been
contamination from other races like Carnica that did not show up, but
such errors are likely to be of similar order to the ones established
for definite.
****
I should add that it is common to use the body parts from 50 bees to
make an assessment, but if you already know the details of the Queen and
Drone parents, then a sample of 30 is considered OK as long as nothing
unusual shows up, then you have to look again with bigger sample and
more criteria.
Regards & Best 73s, Dave Cushman, G8MZY
http://website.lineone.net/~dave.cushman or http://www.dave-cushman.net
Short FallBack M/c, Build 6.02/3.1 (stable)
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