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Subject:
From:
Dennis Murrell <[log in to unmask]>
Reply To:
Informed Discussion of Beekeeping Issues and Bee Biology <[log in to unmask]>
Date:
Sun, 14 Oct 2001 11:57:20 -0600
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Hello Bob and Everyone,

 Bob asked:.
> When did you install your SMR queens?  What are your 24 natural mite
> fall amounts now?

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.

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 think re infestation, as Bob stated, is a major problem in my area.
Mites are resistant to Apistan here with only 30% to 40% being killed.

By mid September natural mite fall in these hives was about 150 per day
with many of the mites being immature females and males. I saw a few bee
damaged mites in the debris.

Two weeks later the majority of the mites were immatures and males. 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.

Now natural mite fall is generally less than 25 mites per day in these
hives.

Other hives, primarily Carniolans, didn't follow the trends noted above.
Natural mite fall continued to increase very slowly from just a few mites
at the beginning of the season, to less than 50 mites per day mid season
and decreasing somewhat toward the end of the season as brood rearing
slowed.

Hive inspections this weekend indicate that the Carniolans have started
the same process began earlier by the SMR bees. About 100 mites/day
containing bee damaged mites were seen and the bees were opening sealed
brood at the purple eye stage.

Bob asked:
> You are not using a chemical and getting all these mites and noticing
some with chewed parts are you?

No chemicals of any kind have been used in these hives.  Initially these
hives were prepared by shaking Russian bees onto 4.9mm cell foundation.
After they were established, they were treated with powdered sugar to
minimize any initial high mite load.

When mite fall reached 100 per day, I treated with powdered sugar to
offset any mite immigration. The results were surprising. Initial daily
mite fall from the treatment was around 25 mites! Less than that for a
couple of days and then back to around 100 per day. It seems that the
sugar treatment interfered with the cleaning the bees were doing
themselves.

My Russian breeder has also followed this trend, but without a single
damaged mite being observed.

Hope this helps.

Best Wishes
Dennis Murrell

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