Hello Chris & All,
I have great respect for Bailey but when TM entered the U.S. in the 80's
half the commercial hives were lost. partly because Bailey had said the
below.

> (Bailey 1958;1961) showed that, contrary to the received opinion,
A.woodi, [tracheal mite], whether in natural or experimental infestations,
does  not cause any outward sign of disease.

>It is detectable only by dissection and
microscopical examination of individual bees.

A field test as suggested by Ruary gives a good indication of TM
infestation.

 >Moreover, although it shortens the
life of an infested bee, it does so only by a barely detectable amount, an
observation independently confirmed in N.America (Royce and Rossignol 1990).

In Europe you mostly run dark races which had been exposed to TM. In the
U.S. we mostly run Italian bees which in the 80's had NEVER seen a TM. My
Italian bees have always had problems dealing with TM. Treatment once a
year costs around fifty cents plus labor. Left untreated for a couple years
they start crashing in winter. I would rather use my high production Italian
bees and treat than use so called TM resistant strains I have tried. Some
are TM tolerant and some from the same breeder are not. A crap shoot!

>Only the relatively few colonies that have more than 30% of their bees
infested   are more likely to die than uninfested colonies - because of the
slightly  shortened lives of infested bees - and then only in late winter or
early

Maybe in England but we test and spend big bucks for menthol to control TM
in many large operations. We consider over 10% very serious but again all
beekeeping is local.

If the all the above Bailey said was true in the U.S. would we have lost
over a million commercial hives to TM in the 80's when TM arrived?


Bob


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