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Date: | Mon, 15 Oct 2001 04:57:00 -0500 |
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Hello Dennis,
As I said in the earlier post. I believe you installed your SMR queens in
hives with a high varroa count. According to Dr. Marion Ellis a hive with a
natural mite count going into a Nebraska winter with a natural mite count
over 30 will not likely survive. Nebraska winters are tough and none of my
commercial Nebraska friends winter in Nebraska except Dr. Ellis and hobby
beekeepers. All go south. Since Marion wrote his article "Living with
Varroa" many have put the threshold higher (Delaplane and Webster (2001).
The new book *Mites of the Honey Bee* puts the threshold higher at 117. The
book says a threshold over 117 can be treated but you can expect to lose the
hive( pg. 234). Dr. Delaplane puts his treatment threshold at around 75 (I
believe without looking up his article in ABJ). These counts are for August
but do not take into consider severe winter and general hive condition. Why
(i n my opinion ) the process is more complicated than these people say but
these are general guidelines. Many different opinions are around Dennis. You
can double check your natural mite count with a roll . Threshold is 15 using
a 300 bee sample (Webster 2001). To be accurate you need (in my opinion) to
count the bees in the jar afterwords. With the Sugar roll (Dr. Ellis) this
is not possible (or not easy) but you do not kill bees. According to the
above and in my opinion you did indeed install your SMR queens into hives
which were close to a crash threshold for August. I am only trying to help
out and give my opinion. You have provided accurate information so I can
give my opinion (backed up by the experts). As I said in my earlier post on
Bee-L we chose to treat this fall in our SMR installed hives and start the
two year test in the spring with a normal varroa infestation coming out of
winter . I can not see any hive with a infestation level as high as yours
surviving a Missouri winter (150 mite natural fall)
. Starting next spring we will leave untreated and monitor. If we had got
our SMR queens last March I would have left untreated this fall Any which
would have had a high threshold mite count would have been treated and
removed from testing.
. I care little what the rest of the beekeeping world thinks of my way of
doing things but my way is logical to me. How long have your Russian queens
went untreated. My quess is they were approaching the two year *crash
point*. If they were in their third year untreated I would say you could
have bred from the lowest mite count Russian queens and perhaps had a
somewhat varroa resistant bee.
If approaching the two year mark I would say your Russian queens were no
more varroa tolerant than most mellifera. Only trying to be honest. I admire
what you are doing Dennis. Maybe I should have sent the reply directly to
you but feel you are like me and doing your work mainly for your own
information.
> I replaced Russian queens with SMR queens on 7/10/01. Natural mite fall
> after 24 hours was typical as tracked in previous years at 2 to 50 with
> the majority less than 25. No damaged mites were observed.
I do not see damaged mites till the count climbs to around 30.
>
> But by August 15th significant changes were noted. Bald headed brood
> uncapped at the purple eye stage by the bees was observed in some of the
> hives. Varroa were found in the bald headed brood. No varroa was noted
> in cells uncapped by myself on the same frame, even in the drone brood.
> Natural mite fall began to increase also. Almost all of the fallen mites
> were mature females. Some mites were seen externally on the bees
> themselves.
I assume you did not do a mite count on Aug. 15th. Five weeks later your
bees should have been close to threshold in my opinion. All the signs you
list above are found in hives approaching threhold.
> I think re infestation, as Bob stated, is a major problem in my area.
reinfestation totally screws up testing. If reinfestation occurs in the two
year period I am testing (or our researchers) the tests are NOT accurate.
Could be why your Russian queens are getting a high varroa count and not
because of the bees tolerance of varroa. Isolated areas are hard to find but
are required for varroa testing to be accurate. Several times we had to
treat three times with Apistan in 1995 to keep down reinfestation numbers
before winter. We pulled supers and treated early because of mite counts on
a number of hives. We still had heavy winter loss. Reinfestation mite
numbers can overwelm any hive.
> Mites are resistant to Apistan here with only 30% to 40% being killed.
I do not know how resistant the mites in your area are to fluvalinate
but in Georgia Dr. Delaplane found hives in which Apistan was not working
at all (ABJ article). They then become vectors for varroa and the problem is
the same as when we had all the trouble when the feral hives were getting
threshold mite counts and being robbed. When I got my first fluvalinate
resistant mites I found those mites in only a couple hives in a yard but the
number of hives with resitant mites grew. I moved the Apistan resistant
hives to a remote yard to wait for a solution. My Italians will rob a weak
varroa ridden hive in a heartbeat.
The majority of fallen mites were showing bite marks in the SMR hives. One
> hive had over 90% of the mites damaged. Natural mite fall had decreased
> to less than 100 per day. External mites were rarely seen.
We still have got work to do in getting a varroa tolerant bee. It would seem
that the SMR trait helped but the bees were simply overwellmed by varroa. I
would treat and hope for the best or introduce the SMR queen and several
frames of bees and brood (nuc) into a treated strong hive
for this winter
> Now natural mite fall is generally less than 25 mites per day in these
> hives.
Everything you have said makes perfect sense up until now. Let me ask a
couple questions. Has your bee population dropped accordingly to provide
these lower mite counts? If you suspect reinfestation how do you explain
the low mite counts? How do you explain the drop from 150 mites a day to
25?
These hives are at a level I might not treat at now. Strange. SMR could be
rewriting the varroa books. I see no other explanation. Please recheck and
report back. I plan to say little about my SMR until after the SMR bees have
passed the two year mark. In truth we have a couple hundred open mated SMR
queens installed and treated ready for winter. Some will most likely winter
in Texas. Our testing will begin in the spring. We are a little hesitant to
switch entirely to SMR until we prove to ourselves the move is worthwhile.
My SMR queens are mated to carniolan survivor drones and my partners to a
Marla Spivak hygienic queens drones.
My experimental hives never produce any honey and I have added frames of
honey to get the survivor untreated bees to winter. It was either add honey
or watch die last year.
Did your Russian bees produce honey? What about the hives you introduced the
SMR into? What about the Carniolan hives with the average untreated mite
counts? How long have your bees been on small cell?
Bob
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