" relative-adaptation analysis is a tricky game"

The above quote is a gross understatement.  We have recently had a whole
list of scientific publications on how bees might deal with varroa.  The
suggestion is breeding for one or more of these biochemical pathways might
solve the problem.  I have long maintained such directed breeding is almost
always a dead end.  In the first place no one should care how the bees
control mites.  How they do it is an artificial target.  The real target
is to control mites.  The best time to worry about how the bees do it is
after you have bees capable of doing it.

So, if you want to enter a selective breeding program the best choice is to
know nothing about the various alternative ways bees might control mites.
Rather, simply select for bees that do what you want, namely bees that
control mites.  We have excellent ways to get a handle on how well bees
control mites.  Things like alcohol washes are cheap and fast.  A wash does
not require fancy or expensive equipment.  You can do a wash in the field
without any sort of laboratory.  A wash is more than accurate enough to
determine which bees control mites and how well they do it.  That is all
you need to direct selection in a breeding program.

Such a program is ideal for honey bees due to queens mating with multiple
drones. There are real good DNA reasons to expect this kind of breeding
program to work and equally good reasons to expect a biochemical pathway
directed program to lead to a dead end with bees that may control mites but
lacking other essential commercial characteristics.

Further, there is a good chance that no single biochemical pathway is going
to solve the problem.  Most will do no better than get you part way to the
solution.  How valuable is a bee that is able to cut the mite counts in
half, but that is the limit?  The contrast is when you stop trying to tell
the bees how to control mites and just select based on mite counts you will
automatically include multiple ways to control mites.  This also gives you
back up in the bee.  If the mites manage to end run one of the selected
biochemical pathways you still have several others operative.  Which would
you rather have, a bee that has one pathway that will control mites by 80%
or several pathways that each control mites by 50% each?  This is exactly
the same argument as to why you want to use several different chemicals if
you control mites by chemical treatments.

It has been understood for a long time that the best way to avoid
resistance development to any given chemical is to use only enough to kill
from 50% to 75% of the mites with any given chemical and to use several
chemicals with different modes of action.  The problem with doing such a
scheme with chemicals is they are expensive and application labor is
expensive.  It makes no difference if you are killing mites on bees or
weeds in your corn field. No commercial guy wants to do so many
applications.  But, if your breeding program builds in multiple genetic
routes all at the same time it is desirable if you get a mite resistant bee
that does multiple treatments of mites by multiple biochemical routes.

Now what does history teach us?  The type of breeding program I have
suggested has been in use for the last couple of thousand years in various
plants and animals.  Those old time breeders had no choice as things like
lab tests simply did not exist.  Yet, they accomplished wonders far greater
than mundane mite control.  Compare that with the last 25 years of
selective breeding programs in bees that were directed by things other than
mite counts.  I include hard Bond in that bunch.  Not one of them has
produced a line of queens that is acceptable in the qualities a commercial
beekeeper needs to keep dinner on his table and at the same time produced
queens that reliably controlled mite counts.  Are we so dumb we will keep
beating our heads on the same old concrete sidewalk because it feels so
good when we stop?

Bottom line is I think it is clear that the fancy directed approaches are
not working.  The best of them have gotten us only part way to the desired
target and lots have gotten us no place at all.  This poor progress was
predictable in my opinion and tells us what to expect if we continue this
same approach.  I do expect by and large we will continue doing what we
have been doing.  It is easy to dress up some grant application with lots
of fancy technical words and lit references so it all looks like wonderful
science versus writing an application to spend money on a alcohol wash
directed breeding program that will not generate publications in any
fancy biochem journal.  After all, the grant reviewer most likely knows
nothing about designing a breeding program that will actually work.

I do see real hope for directed mite breeding programs in the not too
distant future.  We need technology to catch up and get less costly first.
They are still going to be done by someone with a lot of money to spend.
But even when those DNA technologies are available the winning formula for
a breeding program is going to be DNA stuff directed by mite counts.  In
the meantime a program based on nothing but mite counts is the best bet.
And progress in such a program is not going to happen to anyone running 50
hives.  That is simply too small for all kinds of obvious reasons.  It is
also not going to happen with continued introduction of new stock,
including foreign drones drifting into your breeding stock.  That is part
of the reason 50 is simply too small.  As another poster has observed in
improving honey production by selecting for what you actually want and
using a large enough breeding population can show positive results in a
single generation.  Any program that is not showing progress in any three
consecutive generations is waiting for a new mutation to come along and
that can be a long wait.

Dick

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