Randy has provided excellent evidence dispelling the notion that N. ceranae
has been around for "decades" undetected.

I'll address the issue of N. ceranae being somehow ubiquitous,
opportunistic, and exploitive of "stress conditions".

> N. ceranae... became prevalent
> as an opportunistic infection
> due to stressors such as varroa,
> virus, or pesticides (or all of these).

Statements like the above have become a standard way for research and
extension folks to qualify ambiguous study results in presentations to
beekeepers. Most often, they don't offer a clear solution to the
problem/disease/pest beekeepers to use, and sometimes they do not even offer
a method for reliable field screening or tracking of the problem, so they
tell us to "reduce stress" on our bees!

I view these types of statements as hand-waving and weaseling. It is fairly
easy to create a situation where bees are "stressed" by confinement when
overwintered, by infestation with varroa, or by exposure to pesticides,
fungicides, etc.  We know exactly how to do these things, and even how to
precisely vary the "dose" of each form of stress.  But in cases where these
stresses have been studied, varroa and pesticides being the most-often
studied, we don't find higher nosema levels when we expose the bees to more
of the "stress".  We don't find ANY diseases increasing, except for those
virus-driven problems clearly resulting from higher levels of varroa
infestation.

So, "harrumph!" I say.  Show me a dose-response curve for a specific type of
stress, or don't blame beekeepers for somehow "stressing our bees" as a
factor in the problem.  (My own bees are so pampered that when blooms wilt
in Central Park's Conservatory Garden, skilled professionals in matching
coveralls replace them with new plants from the greenhouses that are
blooming or will soon bloom!)

DeRisi's paper in PlOS One, 6/7/11 tracked N. ceranae and N. apis
extensively throughout the season in several large migratory operations, and
Figure 2 is of great interest:

http://www.plosone.org/article/info%3Adoi%2F10.1371%2Fjournal.pone.0020656#p
one-0020656-g002

In regard to N. ceranae, does moving to Almond holding yards in California
cure nosema, or does it simply take 3 treatments to kill it off? Does
Fumagillin work at all in less than 3 treatments?  We clearly need to test
again after treatment.  But look at how it becomes nearly universal in July
and August, yet fades away in December!   What stress could hives experience
in South Dakota in July and Aug.

In regard to N. apis (tracked only in the pie charts) we see it in spring,
it disappears without any treatment by June, yet it returns in August and
September, which should be a big surprise to those who want to think that we
"understand" N. apis well.

So, if one wanted to think of "stress" for bees, one would think that the
holding yards in California would be the most stressful, and times of bloom
would be less stressful.  But N. ceranae in the Derisi study seemed to
thrive at times of apparently minimal stress, and dwindled when one would
think the bees are enduring the worst conditions possible.

Not firmly conclusive, but pretty convincing, I'd say.

In regard to my rant about "stress", I think it is important to recall that
an "opportunistic" disease or infection would plague the results of every
study done on the acute problems of bees.  But bees are among the most
biochemically simple and fragile of God's creatures, so much so that many
people speak of how honey bee social behavior is a significant part of their
"immune system", given that honey bees express only two-thirds as many
immunity genes as solitary insects, e.g., mosquito or fruit fly.  Therefore,
I don't think individual bees survive acute problems long enough for
"opportunistic" diseases to become a serious factor.

Of course when a colony population dwindles down to the "doomed" level, all
sorts of things crop up.  We used to call this "PMS" and "Idiopathic Brood
Disease Syndrome".  One will note that killing off a yard with varroa or
pesticides/fungicide cocktails will produce amazingly similar symptoms.

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