>> have you tested and found that you actually have any/all
>> of these problems, or are you perhaps treating for
>> pests/diseases without justification?

Mark said:

> I haven't noticed any of these problems but my beekeeping
> mentor told me to treat for these every fall (and my reading
> led me to believe this wasn't a bad idea -preventative measures?).
> Perhaps this is wrong (?) Help me.

The biggest problem we have with most beekeeping "treatments"
is that the target disease or pest becomes resistant to the
treatment.  Varroa have quickly become resistant to multiple types
of treatments.

Therefore, one wants to use drugs and pesticides in one's hive
only when necessary, which requires learning how to detect
various problems.  This is the essence of "Integrated Pest
Management", a worthwhile effort that has worked wonders
everywhere else in agriculture, and is slowly finding its way
into beekeeping.

For each of your suspected problems, there is a specific diagnosis
process that is not difficult for a beekeeper to perform.  One of the
best online references I have found is this:

http://maarec.cas.psu.edu/pest&disease/pppdIndex.html

It tells you how to test for just about every problem you can
imagine, and has nice color photos to aid your diagnosis.

Nosema - http://maarec.cas.psu.edu/pest&disease/slide39.htm

Foulbrood - http://maarec.cas.psu.edu/pest&disease/slide10.htm

(Keep reading and clicking "Next" until you get to "European
Foulbrood", which is a different disease.)

Mites -  http://maarec.cas.psu.edu/pest&disease/sl10.html

(Keep clicking "Next" here also.)

As for the "timing" issue, the major points are:

a) Getting the supers off the hive before treating for anything

b) Doing so when it is still warm enough for the chemicals
    and medications to have some effect.

In short, if the bees are clustering, they are neither eating medicated
syrup, nor are they coming into contact with the Apistan strips.

If you find an actual need to do so, there is no problem with (for example)
putting Apistan strips in the brood chamber and feeding one medication
or the other in syrup at the same time, but I do NOT mix two or more
medications into the same bucket of syrup, simply because no one has
ever told me that this is OK,  and I recall Honey's line from "Who's Afraid
of Virginia Woolf?" - "Never mix, never worry".  (Comments, anyone?)

If the web pages above are not enough, another good reference is the
USDA ARS Agriculture Handbook 690 "Diagnosis of Honey Bee Diseases".
Be sure to pick up the "revised in 2000" version.

At EAS 2002, I saw a very nice Canadian government publication
that included very good color photos, similar to the MAAREC
website mentioned above.  Does anyone have any ordering information
on this? (I should have bought a copy...)

        jim