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Date: | Mon, 14 May 2001 08:48:34 -0500 |
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Hi Everyone,
Bob asked:
1. Are the hygienic bees removing all but the most stubborn scale?
2. Is the amount of scale low because we are seeing the Terramycin resistant
strain?
3. Why are we not finding the ropy stage if these hives died over the last
winter. Are the hygienic bees removing the ropy stage? Is this really a
good thing or is this spreading the disease even faster than in the old days
when the bees simply quit using the AFB brood frame. In the *old days* the
beekeeper would have to eventually notice the AFB problem as the number of
frames the bees were ignoring built up. If what we are looking at IS the
work of hygienic bees then the problem is becoming harder to detect until
the final stages (in my opinion).
Bob
Ps. Keep in mind the two policies used by the majority of beekeepers for
AFB are
1. cull & burn
2. treat with antibiotics and prevent the active disease leaving the spores.
This option with Terramycin is fast disappearing. Hopefully a new antibiotic
will be registered for AFB use in the U.S. before the smoke from burning AFB
hives will be seen for miles.
Questions:
1. Interesting observations regarding AFB scale in used equipment. The hygenic bees may also be preventing more scale by removing infected larvae before they can dry down to scale. For some reason they are not getting it all but if there is too much disease they can be overwhelmed by it so that could be part of the problem or as you suspect they may just not be able to remove some of the scale. Hygenic bees usually remove diseased larvae before they become infectious and long before they become scale. I have seen partially removed brood in hygenic colonies that were white with no visable disease at all but the bees were removing them. Couldn't tell why they were being removed but they were.
One question here. Were these colonies killed by AFB or something else? If a colony dies from AFB there usually is lots of scale but if a colony that is resistant is dealing with the disease but still has a small amount of infected brood that isn't being removed and dies from something else you would expect to find little scale. Resistant bees can and sometimes do get AFB but will usually clean it up over a few weeks time. The colony is able to handle the some disease and clean it out over time but it does take some time and you may find a few cells of disease during this process. The other question is how much scale were they given? Even strongly hygenic colonies that are given a lot of scale can be overwhelmed by it.
2. No. TM resistant AFB produces plenty of scale - whole frames of it just like you used to see and it looks and smells like AFB. The only difference that one sees is it does not respond normally to TM. Even in properly treated colonies you will still see active AFB including ropey larvae and scale being produced. TM resistant AFB is not the reason for you only finding scattered scales.
3. I suspect you are not finding ropey larvae simply due to the timing - it has been too long for the larvae to remain in the ropey stage they have dried to scales.
Again interesting observations. I think the hygenic stock will help with disease management but is not the total answer. Actually, most beekeepers will probably see more benefit from their resistance to chalkbrood. Chalkbrood causes economic losses to beekeepers by bleeding away hive populations.
USDA honey bee researchers are testing alternative antibiotics but the folks at the beltsville lab may need to hear from more beekeepers on the need for such a treatment.
FWIW
blane
******************************************
Blane White
MN Dept of Agriculture
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