First a little review. I took 40 hives into winter. All hives had been treated with MAQS in mid-August and then with oxalic acid vapor in mid-September and again in mid-October. Random mite checks showed 0 to 1.6% mite levels, which should be acceptable. All 1st year hives were heavily fed 2 to 1 sugar syrup beginning mid-August. In early October I graded the 40 hives by looking at the number of frames in the upper brood box that were covered with bees. Strong had 8-10 frames covered with bees, medium 6-7 frames and weak 5 or less frames. The results were 27 as strong, 10 as medium and 3 as weak. Earlier I had eliminated several other weak hives by combining them with other hives. In addition to good mite control it is recommended to NOT try taking weak hives through winter. So I almost complied with that successful wintering rule. There were 24 hives headed by Russian queens, 8 by Ankle Biter queens, 5 by Carniolan package queens and 3 miscellaneous ( one Italian and two unknown from swarms).
So now we are half way through winter. There has been about 6 nights with below zero weather. However, we did have a nice mid-January thaw when the bee clusters were able to relocate.
At this point I have lost 7 hives or 17.5%. Each loss hurts but the losses are a lot better than last year when I had already lost 33% by February 1st. Hopefully I am learning something; if I only listen more closely to what the bees are telling me.
-Losses by relative hive strength are 3.7% (1 of 27) for strong hives, 40% (4 of 10) for medium hives and 33% (1of 3) for weak. Another confirmation of that wintering rule of only trying to overwinter strong colonies.
- By queen type the losses are 4% (1 of 24) for Russians, 25% (2 of 8) for Ankle Biter, and 60% (3 of 5) for Carniolan. The Carniolan queens were “run of the mill” package queens from California; so I suspect they have little if any mite resistant characteristics (genes). Russian and Ankle Biter hives that went into winter as strong hives are all still at 100% survival. So maybe the lesson here is to replace package queens with more winter hardy and mite resistant strains as soon as possible.
-So far there has been a slight difference in survival rates for wrapped (lost 3) versus un-wrapped (lost 4) hives. In previous years there was no difference. I will have to wait until spring to see how this ends up.
I see in the weather forecast that there are a few more below zero nights in the offing. It’s another two months before the bees can begin foraging for pollen. After spring arrives I will try to take a mathematical look that takes into account all factors; queen type, wrapped versus unwrapped, fed versus unfed and initial hive strength. So far by studiously applying the applying the wintering rules I have seen a significant increase in winter survival over previous years.
The overwintering rules as I know them right now:
1) Only try to overwinter your strongest hives. Eliminate dinks (weak hives) by combining with others.
2) Know your mite levels and treat as necessary. Mites and the associated viruses kill more hives than starvation or cold.
3) Heavily feed startup colonies since they are unlikely to have stored enough honey to see them thru the winter. Feeding all colonies after removing surplus honey isn’t a bad idea.
4) Incorporate superior mite resistant queens in your operation. (I lost 7 of 9 package queens from last April til now.)