Hello Chris and Janet and others who responded to this post,
        The symptom you report indicates dysentary. Dysentary is simply diahrea
and can be caused by poor quality winter stores, inadequate winter
flight, nosema, other infections. It is also associated with prolonged
damp conditions and or tracheal mites.
        My personal observation is that nosema has increased since the arrival
of tracheal mites and that it is now a serious problem, at least here in
NY. As I've said before here on Bee-L, I think more beekeepers should be
sending bee samples in for nosema spore counts. The "do an experiment
method" may be fun but in the long run expensive, just sent bees to the
lab and you'll know if your bees are infected. The scientists, notably
Dr. Furgla, have already proved fumagillin works.
        Remember folks, winter losses are just the tip on the nosema iceberg.
Nosema levels peak in mid to late summer in the north. Nosema reduces
the length of a bees life by up to 33%. What is a bee doing during the
last 33% of life? Ever see hives that look normal except that they were
not making as much honey as other colonies? Of course there are other
factors but nosema is one. And it has rescently been identified as an
important factor of queen performance.
        As someone else mentioned, equipment can be contaminated with nosema
spores. This can be rectified with a good medication program using
fumaggillin. Dr. Furgala recomended a 2 gal. treatment each fall and 1
gal. each spring as a MINIMUM treatment to control nosema. Although
expensive it is more cost effective that replacing equipment especially
if you depend on an income from your bees.
        Regarding the "Pulling a bee apart and looking at the mid gut?" test
for nosema, I've found this is reliable only when the result is
positive. Often when the result is negative a spore count indicates a
high infection rate.
        Hope this helps,  Vince
 
PS to Mr Iannuzzi- how much data supports your opinion of nosema's
importance?
 
Chris and Janet Sauer wrote:
> Since we're on the subject of dying bees... I've just lost a hive I started last spring.  It has long streaks of brown feces at the entrance indicating Nosema.  I treated the colony with fumidil in the spring and fall last year with the correct amounts mixed in syrup.  Is it still possible for Nosema to kill the hive?  Another interesting sight: when I pulled apart the top brood chamber yesterday, there were dead bees in the comb as if they were starving, but there was capped and uncapped stores on the same comb.