This thread is a follow up to the "Winter deadout obvious...yes". I am hoping folks can help me learn from this.
These are pictures from 2 foam nucs very similar to those Bluebee has been building:
https://picasaweb.google.com/107355150238360566862/DeadNucs?authkey=Gv1sRgCMTWgtKG19eJ1wE#
I think they just got too small to stay warm even with the insulation.
some background:
Both were started from "virgin" swarms at the end of june/beginign of july. Russian hybrids. They drew out all the comb you see. And were fed heavy last weeks of September.
Nuc 1 had the top vent closed and was actually less populous than 2 when I looked last in fall.
Nuc 2 had a small 3/8X3/8 vent at top. It also showed some trouble at the end of fall. expelling a handful of larva and DWV bees. I could see some dead varroa on the entrance tunnel at that time. No treatment. This Nuc also seemed to die in "stages" as the large pile of dead bees under the cluster had capping wax on top of them. UNder the pile of dead was a handful of removed larva and pupa. This Nuc also brought in pollen long after any other hive.
Niether had any brood I could see.
In both when the bees on the comb face were removed the empty cells under them are filled with head in bees....right next to capped stores.
Our temps have been crazy. Warm late fall. A couple of short cold snaps with nights at -10F followed by rapid warming to mid 30's low 40's...the same yoyo that many are seeing this year in the north.
Some questions:
Is the small amount of streaking I see in Nuc 2 normal or indicative of nosema?
What sort of a mite load are the number of dead varroa on the bottom of nuc 2 indicative of? It seems small to me compared to the stories I hear.
They seem light in pollen is that a reasonable assessment?
Any thoughts much appreciated.
It didn't look like a nosema problem to me. I get a LOT more streaking than that with nosema.
Can't speak to the mites; not a big problem in my bee yard. A few dead on the bottom board would seem non lethal to me.
I think they starved/froze. Staved because they were too cold to move up/over to new stores, even if just a cell away. Maybe there is some detrimental effect of too much insulation? I don't know. Maybe your clusters were just too small?
What really stuck me in your photos was the smallish size of your clusters. That few bees probably would need electric heat to survive in retrospect. Not only were they small, but it didn't look like they've eaten much which suggests they've been small for a while. If looks like the bees did a great job of building up those nucs, so I would have expected to see more dead bees in there. My deadout nuc had a LOT more bees and it was started about a month later than yours (August 2nd ). Mine where Carniolean mutts. Where did all your bees go?
My instinct was they were just too small and froze out...quite possibly in 2 stages corresponding to our 2 cold snaps...the dead piled under the cluster had a distinct "layer" with a dusting of capping wax between them.
But for me it is just a guess. I have no baselines to compare too....there is no substitute for experience. That is why I am here asking for input on what can be seen.
I don't know how many bees I should have had in there. I know when I closed up nuc 2 in fall it seemed as packed as possible, but again what do I know?
Electric heat crossed my mind....but that isn't the direction I want to go for a lot of reasons.... including the frequency and duration of our rural power outages!
I have realized that I messed up the captions on the frames...at least the numbering, because I didn't bother with photos of the frames that were nothing but untouched capped stores.
Hopefully I can get some more feedback.
This was my first attempt at overwintering nucs and it seems like with yesterdays inspection, I have failed miserably. Ive lost 2 out of the 4 and it looks to me like excessive moisture was the culprit.
windfall, the pictures of your small clusters look like what I found when I did the post mortem on the small group of bees I was trying to save (the ones I put inside my barn with the heat lamp). They had warmth from the lamp, and you had additional insulation, but in the end (my humble theory) they were still too cold to move around and get the food -- eventually succombing to cold and starvation.
I was thinking if I ever did this again (hopefully, I won't have to) that I'd try one of those oven thermometers that lets you put the sensor on the inside and has the digital readout on the outside.
K9, 2 of 4 doesn't sound like miserable failure to me, but winterr isn't over yet. Besides, failures are not miserable unless you learn nothing from them. Are you going to modify the remaining 2 in any way?
Alicia, thanks for the input. Small cluster is what everyone keeps telling me. What would also be helpfulk is an idea of how much bigger I should have liked them to be... twice as large? 3X?
Even though I told Bluebee I didn't like the electric heat so much, it would have been tempting to have the option to give them a little help those nights that it drops in to deep cold. I can see this as more realistic if I had known in Fall they were too small....although better to have combined them at that point I guess.
Sure it would have been pampering them, but a couple of dollars in electric heat is way way cheaper than a new nuc in spring (if I can get one), heck it's still cheap even if all I got out of it was a live mated queen and a handful of attendants come spring. It would still give me options to play with as I learn. I like to have as many resources "in house" as possible.
i am not sure i back the starvation as these bees were on the honey, not 1 in. away. The cluster of Russians are usually very small but this here is really small. My take is more about moisture. Why was the vent closed? What kind of air circulation system did you have in place? A nuc is a small space, with small openings and moisture has a hard getting evacuating, esp. in styrofoam (not breathable unlike wood). This is one essential aspect of overwintering.
One of the real beauties of a well insulated hive is they are very cheap to heat electrically. Pennies on the day. Cheap insurance against brutal cold. A system with a trip point about 10F or so seems like a good idea for me. Last winter I kept my electric heaters on pretty much non stop. I had colonies about your size survive that winter when the losses of full colonies in Michigan were over 60% last winter. We had a normal cold, brutal, winter last year. No doubt, electric heat works. It's the process of determining how much heat to add and when that is the challenge
As for your cluster size, it looks from the photos that yours were about softball sized? My single story nucs are about 2 to 4 times that size. My bees are Carni + Italian mutts.
I agree with OrganicFarmer that moisture can be an issue with Styrofoam.
I just came in from cleaning up a "full size" hive that also tanked.
It had a much much larger cluster, not counting the 3-4 cups of dead bees I raked out of the clogged entrance a few weeks ago.
But other than that it looked almost exactly the same. Bees head in in every cell the cluster covered, stores within a cell or 2.
It also appeared to have died in 1 or 2 stages. With 2 obvious layers of dead on the bottom board and rising up the frame space separated by a layer of wax debris (cappings?)
This hive was not insulated. It was 2- 8 frame deeps. NO sign of condensation anywhere inside, no top vent. No brood, and very few varroa on the BB...maybe 25....I did not count but had to look to find them. No dead pupa or DWV bees noticed. Going into fall this hive was one of my most populous.
What is perhaps noteworthy (or perhaps not) this hive grew from a "False swarm split" that was made in an attempt to stop a hive from swarming. That attempt failed and the 2 swarms that were issued were captured to start the 2 nucs that also died. So they are all related, with this larger hive having the original queen.
My remaining hives all sound alive and all came from a different line.
Is a connection likely/possible. Some kind of virus or disease issue that would not show it's head till winter?
OrganicFarmer, sorry I meant to respond then kids started jumping on me.
I don't know much about bees yet but I do know wood. I build wooden boats for a living. If you think the wood on your hives breathes moisture at a rate anywhere near comparable to the bees production.....well I can point you to specifics of moisture migration by species but it is pretty darn slow even in pine. Very little moisture is getting out that way especially in winter at temps below freezing. Certainly wood can act as a buffer if dry (below 18-20%MC) by absorbing moisture (wicking actually) quickly into the first 1/16" or so but after that it slows way down.
These were definetly an experiment. And I am open to the idea that humid air contributed. But I am pretty sure there was no "dripping" on the cluster I read about. The core was all fresh white cedar which shows water staining very readily. I left the vent open on one and closed on the other to compare. Top vents seem pretty controversial with folks, I don't have an opinion yet so I wanted to see what happens in my specific local, and I didn't see much point in using full body insualtion if they were heavily vented. I have a couple of more conventional hives left, and 2 of those use top venting and wide open bottom entrance as laid out by Michael Palmer.
There was almost no condensation in either nuc, just a bit of light frost in the corners...and I mean light. This really surprised me as I have read about folks getting large icicles on the entrances to northern nucs. It could be the insulation reduced condensation by depressing the dew point, or perhaps more likely the undersized clusters just didn't generate that much moisture (they had barely touched the stores) before they perished. I can easily believe if the clusters were bigger (like big enough to survive) that it could have become an issue.
The one inner cover that shows mold, The mold was actually on the top of the cover, and I should have made that clear in the captions. I meant to close the screened feeding hole and forgot. I got some condensation from the vapor migrating into the space between the foam top and the IC and that did drip down but was trapped in that space...it appeared to act as a moisture trap if anything. But it is worth noting that the nuc with the small top vent/entrance (3/8X3/8) did not have this occur even though I forgot it's screend hole as well.