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)
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.
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.