There was an
unexpected warm spell in mid-February before cooling back down to more seasonal
temperatures. That warm spell probably
triggered the queens to begin laying if they had not already done so. It is now only 20 days to the astrological
start of spring. We are gaining about 3
minutes of sunlight per day now.
Surprise, surpise.
Checking hives two days ago I noticed one hive I had written off back in
January had a lot of flight activity. I
assumed it was robbers at work. I was a
little curious about winter robbing so I opened the hive and there was a nice
bee cluster. So I’m like the cat that
swallowed the canary. Now 34 of 40 hives are surviving; 85%! Obviously some of my good fortune must be due
to the milder winter. I guess I can’t
take credit for the warm weather. Here
are some statistics. Good record keeping
will help you improve your overall apiary performance. NOTE: Some hives have the nasty habit of
slowly dwindling away in the spring. For
some reason the population increase just doesn’t kick in; probably because
there are insufficient bees to keep the
brood warm. So come May my survival statistics
could end up being worse.
Here’s what I did last fall:
-All hives were
treated for mites in same manner (mid Aug-MAQS, mid Sept-oxalic vapor, mid-Oct- oxalic vapor). Mite levels were measured in
mid-October in randomly selected hives and were 1.6% or less.
-I heavily fed
all start-up hives and lightly fed most others
-I had mite resistant queens (either Russian
or Ankle Biter) in the vast majority of my hives.
-I eliminated a
few weak hives in the fall by combining them with other hives.
-As a point of
reference I graded all hives by strength in early October by quickly peeking
under the inner cover. I did this in
about 5 seconds so I wouldn’t start second guessing myself. Strong hives had 8-10 frames covered with
bees. Medium hives 6-7 frames. Weak hives 5 or less frames.
A summary of the statistics are:
-Losses by hive strength rating
Strong hives had
a 4% loss.
Medium hives had
a 30% loss.
Weak hives had a 66%
loss.
-Losses by queen type (ignoring strength)
Russian-8% loss
Ankle Biter-25%
loss NOTE: ankle biter hives had a higher percentage of weak and medium
strength hives due to later start-up.
Package Carniolan-40%
loss
-Losses by queen type (with hive strength recognized)
Russian strong
hives-0% Russian medium hives-25% Russian
weak hives-100%
AB strong hives-0% AB medium hives-34% AB weak hives-100%
Carniolan strong
hives-34% Carniolan medium hives-100% Carniolan
weak hives-0%
-Wrapped versus unwrapped hives-Wrapped hive are winning by
a small margin this year. Lost 2 (or
10.5%) of the wrapped hives versus 3 (or 14.2%) of the unwrapped hives. NOTE: Even my unwrapped hives are located
behind a tree wind break to protect them from the prevailing winds. In the previous two years there was no
difference between wrapped and unwrapped hive losses.
COMMENTS:
1)
Hives losses were in the range of 10 to 15% in
the pre-varroa (prior to 1990) era.
2)
The recommendation of only taking strong hives
into winter was confirmed by my data. Next
fall I need to do a better job of eliminating or combining the weak hives.
3)
Mite resistant queen types (in my case either
Russian or Ankle Biter) survived better in my small sample.
4)
Russian queened hives had a slight advantage in
survival over Ankle Biter queened hives. When hive strength is factored in both types
were about equal.
5)
The Carniolan queens received with packages last
spring were a disaster this past winter and summer; 6 of 9 did not make it
through one year.
6)
My future plans are to replace all package
queens prior to winter.
7)
My mite control effort last fall was my most
thorough effort to date. MAQS applied mid-August, oxalic vapor applied
mid-September and mid-October.
8)
My losses always occurred after -10F nights.
9)
Most of the surviving queens (31 of 34) in my
apiary this winter were first or second generation mite resistant stock. Roughly two thirds of those (~20) had queens
that I raised. My amateur queen raising
efforts seems to not have adversely affected these queens or their winter
survival.
10)
From my limited data I can’t definitely say if
the mild winter, improved mite control or the mite resistant queens were the
biggest factor in my improved hive survival.
It may be a combination of the three. Next year I will try to explore this further
by stopping mite control on a few hives.
11)
What worked for me this winter might not work
for you. I am retired and the extra time
I have to tend my hives may be an unmeasurable factor.
In summary: Only winter strong hives, practice effective
mite control, feed 1st year hives, incorporate mite resistant
genetics into your stock, pray for mild
winters.
No comments:
Post a Comment