March came back at us with another bout of cold and snowy weather. But its spring now and I am ready to work with my bees.
In the past few warm days I cleaned out my six dead-outs to see what I could learn. Two of the dead-outs had been classed as weak hives last fall and I would say their loss was due to starvation. Although I had fed those two beginning in mid-August I could not find any honey in the entire hive( 20 frames). The clusters of dead bees were rather small. So I surmise they had been too weak to even pack away the sugar syrup offered last fall. If I had followed the edict to not take weak hives into winter and combined those two hives I probably would have avoided losing them.
One dead-out had the signs of a Nosema infection; diarrhea deposits on the frame top bars. I may need to reconsider my non-use of fumigilan. There were at least 5 full frames of honey in the hive. However, I have not used fumigilan for several years without signs of Nosema.
The fourth was interesting. The cluster was on the left side of the hive. On the right side were 3 full frames of honey. In the middle was a PLASTIC foundation frame that did not get drawn out. I think this bare frame acted a block during the cold weather and prevented the bees from moving to the food supply. The bees are hesitant to draw out plastic foundation except during the honey flow and last year I was culling all undrawn plastic foundation from my hives, but apparently missed that one.
The 5th was a strong Carniolan hive last fall when I graded the hives. There was honey in frames. No signs of Nosema, DWV or other problems. I could blame it on an un-acclimatized California package queen, but really I just don’t known.
The final dead-out had been a marginal Russian hive all last summer and never made any surplus honey. I think it was a case of the beekeeper having a sentimental heart and giving a poorly performing queen a second and third chance instead of just replacing her.
As previously written I had 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 over-wintering statistics are:
-Overall there was 85% survival in my apiary although I think one hive will dwindle away unless I give it a boost with bees from another hive. My survival target last fall was 70%, so I am happy.
-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 their being started later in the summer.
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 were a tie again this year. Lost 3 (or 15%) of the wrapped hives versus 3 (or 15%) 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 either. The following link is a summary of extensive research done in Madison, Wi, which showed hives with and without insulation should survive in this locale.
-There are several top bar hives in my apiary. These hives are not as easy to work throughout the season, but even harder to work in the winter. There is no easy way to feed these hives in the winter. You can’t easily open the top to see where the cluster is. The fragile cold comb will shatter if touched in the winter. Even if you know the cluster’s location there is no way to get emergency feed to the cluster. The only place to put emergency feed is on the bottom of the hive, but the cluster is at the top. Maybe switching over to Russians, which overwinter with a smaller cluster, would eliminate the need for emergency feed.
1) 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.
2) Mite resistant queen types (in my case either Russian or Ankle Biter) survived better in my small sample.
3) 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.
4) The California Carniolan queens received with packages last spring were a disaster this past summer and winter; 6 of 9 did not make it through one year. And I think 2 of the 3 surviving hives had superceded their queens shortly after the package was installed based on their extremely slow buildup. Therefore my future plans are to replace all package queens prior to winter. My long term aim is to completely stop buying replacement packages; hopefully next year.
5) 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.
6) 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.
7) From my limited data I can’t definitely say if the milder winter (only got down to -10F instead of the usual -20F), improved mite control or the mite resistant queens were the biggest factor in my greatly 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.
In summary my plans for next winter are: 1) Only winter strong hives, 2) practice effective mite control, 3) feed all 1st year hives, 4) incorporate mite resistant and local survivor genetics into my stock, 5) replace all package queens, 6)get the undrawn plastic frames out, and 7) pray for mild winters.
My next major project will be to clean the bottom boards on each surviving hive. I do this by reaching in through the entrance with a slim hook and drag out the dead bees before they start to mold or decay. I won’t open hives for a more thorough cleaning until it is at least 70F. It is important to NOT chill the developing brood. Following that I will be waiting for a few warm (greater than 70F) days in succession and begin rearing a few queens. Hopefully mid-April will provide that opportunity.