To Bee-L colleagues:
 
I hope this message doesn't cross the line for being too long for
downloading.  But I think I have observed by the questions asked to the
list that many beginning beekeepers are in the audience.  And some of the
answers I read appear to be based on conjecture and the opinions of others
rather than on the literature, data and experience.
 
I would like to express a few ideas about how we approach Nosema and other
issues regarding our bee colonies.  It is often heard among beekeepers that
they do not have any problem with Nosema, or Honey Bee Tracheal Mites
(HBTM), or brood survivability, or even queens.  But when they are asked if
they had some bees checked in a laboratory for Nosema or HBTM, or if they
measured brood survivability or queen quality, they say no.  I suggest that
without a lab diagnosis or conducting measurements, we cannot tell whether
our bees have these maladies, or whether they do not.  I base this opinion
on the following grounds:
 
a.  I have dissected thousands of bees for Nosema.  When I put the midgut
into a petri dish I observe the difference between the color and distention
or swelling of the midgut between the 25 midguts in the dish.  I only
rarely see a midgut that is so swollen that I can't see the rings around it
or one that is whitish in color.  Yet the samples will have between 4,000
spores (the lower detectable limit) and as high as 3,500,000 spores per
bee.
 
b.  The four hives that had the 3.5 million spores were sampled in early
July on Vashon Island in Puget Sound in western Washington.  They were
managed in an excellent manner, were five deep boxes high and full of bees.
 They each produced a 125 lb. crop that year.  Was I surprised after all
the stories I had heard about Nosema.
 
c.  When we were running 250+ samples of bees for HBTM in the lab in 1985
we checked all samples for Nosema.  The samples were taken in early June as
I recall.  The Nosema levels in wet and rainy western WA samples didn't go
over 150,000 spores per bee.  Only three samples from commercial colonies
showed Nosema in dry eastern WA .  When I checked the location from which
the samples came I found one apiary setting below the surrounding grade
level in a gravel pit (very high chalkbrood levels too), another backed up
against a southerly exposed granite rock bluff exposed to high temperatures
day and night, and the third was in the bottom of a steep canyon which had
a stream flowing through it.  I suggested that the beekeeper move the
apiary out of the gravel pit.  He did so and the bees removed the
chalkbrood in two days!  The observed condition of the colonies - vitality,
temperament, brood survival - improved rapidly.  Nosema appears to be
highest and have the most negative impact on queens and package bees
following shipment, and colonies in the spring if one or more other
maladies are affecting them.
 
d. I have also cut thousands of thoracic disks of bees and put them in a
potassium hydroxide solution to check for HBTM with a microscope.  In many
of these cases I have removed the trachea from surrounding muscle tissue
and looked at it for mites with a 10x hand lens before putting them in the
chemical bath.  I found that often I didn't see mites with the hand lens
but after clearing the muscle tissue for 4-6 hours in the solution I found
between one and 10 mites per trachea.  My observations suggest that low
levels of mites may be missed with a hand lens.
 
e.  My experience has been that Nosema was highest in those colonies which
appear not to build up rapidly in the spring, though HBTM causes the same
symptoms nowadays.  But it is also true that reduced brood survivability,
poor nutrition, and unattractive queens may all occur at the same time in
the hive resulting in a slow building colony in the spring.  So now we have
to measure several things before we can determine the cause of a
symptom(s).  See how complicated these issues get?
 
f.  Beekeepers often notice spotty brood patterns in their hives.  I have
checked brood survivability under these conditions and found that only 35
percent of the cells with eggs I had previously identified were dark eyed
worker pupae 14 days later.  I have checked larval survivability in
colonies over a period of time pre and post feeding of Fumidil-B
(regrettably without testing for Nosema).  I found that pretreatment
survivability ranged between 35 and 60 percent.  Treatment of the six to
eight frame splits in mid May consisted of gorging the bees with four
feedings poured over the cluster (rate of one tsp. of Fumidil-B in one
gallon of 1:1 syrup); twice one hour apart on a 60F day, and two subsequent
gorgings ten days apart.  Sufficient syrup was poured between the combs to
moisten the bees without letting too much  run out the hive entrance.
Three weeks post treatment, larval survivability ranged between 85 and 95
percent.
 
g.  Beekeepers say their colonies look excellent following the use of
unlabeled miticides.  They don't know what the mite levels were before they
treated.  When the right questions are asked, it is often found that they
lost a lot of colonies the previous fall even after treating (using
Apistan) because they let the mite levels get too high.  The remaining
colonies contained young bees with low levels of mites.  The next spring
they use an unapproved chemical, and report the bees looked fine all year.
Of course they would, because of very low mite levels in the spring
(perhaps entirely unaffected by the miticide).  Talk with them in the fall
or the following spring and they report 30 to 40 percent losses.  They will
claim the miticide worked because that is what is being commonly reported,
and they look around for some other thing upon which to blame the losses.
You'd be surprised at the stories I've heard.
 
h.  Grease patties - TM or plain, powdered or granulated sugar.  Many
beekeepers assume that bees eat the patty.  Others think that bees only
remove the patty from the hive in response to hygienic behavior cues and in
so doing they get some TM on their mouth parts which happens to get to
larvae during feeding activities.  To my knowledge neither of these have
been proven by research.  (But then there is so much research published
that I can't possibly keep up with it all, and I don't have a formal
research library at my disposal.)  I do know a beekeeper who fed large
amounts of cheap powdered sugar to a bee colony for winter stores instead
of syrup or honey.  The colony died in short order because powdered sugar
contains cornstarch.  Powdered sugar holds a patty together better than
granulated sugar during comb manipulations.
 
You simply cannot evaluate a colony's health by looking at the bees, though
you may be able to make some observations about the colony's condition.
That is why scientists insist that research colonies be essentially equal
in all respects, that treated and control colonies be used, and accurate
measurements be taken, before any deductions may be made about the success
or failure of a treatment.  But I will suggest further, that there are a
significant number of things going on in the colony, like larval
survivability, queen attractiveness, etc. that are also influencing the
outcome of the treatments we apply.
 
We attribute human behavior to honey bees, dogs, cats, and other animals.
This is the source of many errant conclusions about what bees are doing and
how they respond to what we are doing to them.
 
It is also very import for beekeepers to check out the technical references
available to them in their search for information about diseases and mites.
 Much has been published on the subject since 1983.  Where we have problems
is in determining appropriate bee and hive management techniques for
various conditions.  Here it is easy to get at least 11 answers from ten
beekeepers on any question that is asked.  Some answers are technically
accurate but many are anecdotal observations or repetition of answers that
have been passed around for several years and which are now much different
than the original answer.
 
Does this help you look and think differently about your observations,
perceptions, and experience?  Then I have obtained my goal in writing this.
 
Best wishes all.
 
James C. Bach
WSDA State Apiarist
Yakima WA
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509 576 3041