Ken wrote:
>> But Nosema spores are killed by water (and sunlight, and acetic acid
>> fumes).
>
I replied
> ... going out on a limb. Nosema is a
> paramecium, does not produce spores and thrives in water.
Ken responded, but I won't quote that part. On my part, the limb snapped.
Nosema is NOT a paramecium (which my faulty memory says is a single celled
organism with a whip like tail used for propulsion), Nosema is a protozoa
(plural protozoan). I always get my parameciums and protozoan mixed up.
Nosema is a protozan, I am a paramecium (or at least feel that lowly after
having belched misinformation).
From _The_Hive_and_the_Honey_Bee_, Dadant Press, '92 edition, pg 1098-99,
"The vegetative stage of Nosema apis is not infective (Bailey, 1955b; Goetz
et al.). Spores must be swallowed by a honey bee for infection to be
initiated. It has been shown that relatively few spores are required to
infect workers or drones (Bailey, 1955b, 1972a, 1972b; Kellner and Jacobs,
1978). Spores germinate quickly after entering the ventriculus, and the
epithelial cells of the ventriculus are infected when the vegetative stage
is introduced by way of the polar filament ... In 6-10 days the host
epithelial cell becomes filled with new spores ... Spores that are voided by
infected honey bees remain viable for long periods. They resist
refrigeration, freezing, lypophilization and exposure to microwaves." No
mention is made of water making spores nonviable, although I agree with Ken
that a hygenic beekeeper minimizes risk of transfering problems amongst
hives. Treatment of infected equipment includes fumigation with acetic acid
(80% concentration) or thermal sterilization, "120 dF (49 dC) for 24 hours
destroys or renders spores nonviable." Warning is given that decontaminated
equipment + infected bees = contaminated equipment + infected bees. No
mention is made of irradiation, which surprizingly is also missing in the
discussion of AFB. I have read results of studies of irradiation as
treatment for AFB, I do not recall ever reading anything about irradiation
in regards to nosema. Perhaps George Imirie can add something here.
Fumagillin (Fumidil-B) is the only medication mentioned for treatment of
infected bees. Two gallons of thick (2:1) medicated syrup in the fall
"markedly suppresses nosema infection the following spring". I have
attended lectures where Dianna Sammataro recommended an additional gallon of
thin medicated syrup in the spring.
I was taken to task when I confessed a few weeks back that I follow these
recommended treatments, but I didn't lose any sleep over it. Again quoting
_THatHB_, "It is very important that the volume of medicated syrup contains
the effective dose of fumagillin when fed for prevention and repression of
nosema disease. A study in Georgia has demonstrated that reducing the
recommended dose of fumagillan results in inconsistent and ineffective
repression of disease." It is often hard to get bees to consume a full two
gallons of medicated syrup in the fall, a gallon in spring is rarely a
problem. I know of some fall feeding practioners who double the fumagillan
and halve the syrup (one gallon of syrup, twice the Fumadil-B) and I have
heard stories of pouring the syrup over the bees to force them to consume
it. My practice is to feed a half gallon at a time, refill when empty,
shoot for two gallons. If a hive does not make it to the two gallon target,
I make note of it and watch that hive more closely in the spring (if I am
being diligent with my record keeping, and I confess I sometimes slack in
that area). It occurs to me that I am administering twice the Fumadil-B in
the fall as I am in the spring and I wonder what are the consequences. Is
the effective half in the spring as it is in the fall?
There has been a lot of discussion about this (I know Allen is thinking,
"Check the archives"). If you do check the archives, I'm sure there is
discussion of the high cost of Fumidil and sugar and time and labor to
treat. The costs are offset by increased honey production. So goes the
discussion, I do not know of experiments to quote and the final financial
evaluation hinges on current price of honey. In today's market I speculate
there are a lot less dollars being spent on Fumadil-B and a lot more cases
of nosema going untreated.
Aaron Morris - thinking I should read before I leap!
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