Tom Barrett observed:

> Here in Ireland... the current belief is that we must use chemicals,
> since hives being treated by IPM would be overwhelmed by reinfestation
> from feral colonies which still survive, and from colonies held by non compliant
> beekeepers.

> Thus the perceived wisdom here is that we cannot risk using IPM until
> varroa 'stability' is achieved by varroa becoming reasonably evenly distributed.

> Does experience gained in the USA and elsewhere confirm or deny
> what I have said?

If one is concerned about post-treatment reinfestation, one must admit that
this can happen regardless of what treatment method is used.  IPM, since
it includes the concept of monitoring pest levels, at least has the advantage
of allowing one to know one's pest levels, and know when one has been
reinfested.

Sounds to me like there is a general misunderstanding of what is meant
by "IPM".  IPM can include chemicals. IPM can be simply nothing more
than an attempt to use chemicals less "blindly".  IPM is an approach to
dealing with pests that is simply "smarter" than the blind application of
massive amounts of pesticides to all of one's livestock, crop, or land.

If one thinks about it, one wants to monitor pest levels, and "do the math"
before any use of any item intended to kill pests.  I like to joke that IPM
teaches beekeepers to

        "Put Descartes Before the Hearse"

Now, it makes no never mind WHICH treatment option you choose,
IPM approaches still do at least one of the following:

a)  Lower your costs, by reducing the amount of pesticide you use
b)  Reduce your risks, in that you only use pesticides when you must
c)  Measure the value of your treatment, since you are monitoring pest
     populations all the time.
d)  Allow for repeat treatments if required, which saves some number
     of hives that might otherwise be lost in a "blind" program.

All these are good things, and all these things are accurate statements
no matter if you use voodoo dolls or low-yield tactical nuclear warheads.

I myself like the powdered sugar approach, since I can treat when I
see a mite level start to "ramp up", without concern about contamination
of the honey crop.  It is also cheap enough to allow treatments at little
more than the cost of labor (which in my case, is not an actual "cost",
as I need the exercise, and would otherwise be getting into trouble).

I honestly do not thing that varroa will ever be "evenly distributed", for
exactly the reasons you listed (beekeepers who do not treat at all, feral
colonies, etc).

I hope I helped.

        jim

        farmageddon