> I have only been keeping bees for a few years.  When I started I was
> instructed by the helpful folks at the local bee club to dust with TM
> every spring for foulbrood prevention.  From information gleened from
> monitoring this group, along with other sources, it seems that the
> better approach is to monitor for foulbrood and to take action only
> when needed.  How do I get off the TM treadmill?  Do I just stop
> using it and see what happens?

There has been a great deal of discussion here on BEE-L about use of
oxytetracycline (oxytet, OTC) , so I won't rehash it all here.  In short,
there is no simple, one size-fits-all answer, although there are some who
hasten to say there is.

The answer in any specific case depends on the purpose to which the bees are
put, whether honey is to be extracted or not, and when, the neighbourhood
(and jurisdiction) in which they are kept, the size of the operation
involved, the history of the equipment, presence/absence of resistant AFB
locally, abilities of the beekeeper, etc.

That having been said, much of the discussion archived here was years ago,
when detection methods for AFB were cruder and when the sensibilities of
producers, consumers and regulators were different, and before resistant
disease strains became as widespread as they are today.  In recent years,
the thresholds for routine detection used to search for chemicals in food
has moved from parts per million to parts per billion.  Also, during that
time, additional methods of AFB detection and control have matured (hygienic
stock, radiation sterilization, bee and honey sampling) offering other
potential solutions.  Resistant AFB has continued to spread in North
America, making OTC less useful from AFB control.  OTC, however, continues
to be useful as a preventative against EFB, and is a useful weapon against
AFB in many regions to this day.

As for prophylactic OTC use -- in the absence of clinical AFB symptoms --
popular opinion is now moving against such applications.  Nonetheless,
preventative OTC application is still routinely practiced by many expert
beekeepers, without causing detectable residues, and can be essential to
survival where the locality or the equipment has a strong history of
disease.  Nonetheless, with new detection methods, occasionally minute OTC
residues are being  found in honey, and studies are ongoing currently to try
to better correlate timing and methods of usage to the risk of finding
detectable residues.

Because OTC merely suppresses outbreaks, as opposed to actually killing the
disease, many claim the OTC use makes the situation worse.  However, used
wisely, by capable beekeepers, OTC applications can keep the disease -- even
in badly infected equipment or a badly infected region -- from reaching the
stage in its development where it 'blossoms' and generates billions upon
billions of spores.

In the absence of new infections, over time, the spore load in hives
naturally diminishes due to natural replacement of comb, and natural
attrition, and, if outbreaks can be prevented entirely, the background spore
level in hives decays quite rapidly to the point where the risk are low and
reduced OTC applications -- or none -- may be considered.  At that point,
any future breakdowns should be destroyed or disinfected by radiation.  Only
by experimenting can the beekeeper find out for certain what the natural
breakdown rate (and subsequent loss of bees and equipment)  will be.  Some,
due to the history of their outfit or the known practices of neighbouring
beekeepers, know it will be high and cannot take the risk.  Others may be
able to go 'cold turkey' with little risk.

Those who suggest stopping prophylactic OTC applications, especially in
equipment that contains a high spore load, are actually advocating taking a
chance on having a massive breakdown, which, once spread around, will
increase the future risk to a certainty.  That is the factor that every
beekeeper must consider, and the beekeeper must determine how quickly and
efficiently he/she can find and dispose of any infected material.  For those
who seldom examine their hives, for whatever reason, and/or lack the ability
to locate, identify and deal with AFB when it ocurs, prophyactic use may be
a wise solution, all things considered.

As for applying OTC to an infection when discovered, rather than destroying
the frame or hive, it seems to me that the practice is similar to closing
the barn door after the horse has departed, but it may still be a valid
course in some conditions, particularly where the beekeeper has no hope of
overcoming the disease.

These decisions are not simple.  Assuming that practices and solutions are
not locally mandated by law, only after assembling all the available facts
and considering them carefully with possible outcomes, can the best course
of action be determined for the situation in question.

allen
A Beekeeper's Diary: http://www.honeybeeworld.com/diary/

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