Looking at the bottom board, it appears that there is no insulation below a single layer of core flute. That is a huge area for sub-zero temp to penetrate through.
I’m wondering if snow blocked the entrance, suffocating the bees.
I read the article linked below about hives with screened bottoms- it mentions hives in Australia’s snow country doing very well with screened bottoms- but that assumes no upper ventilation at all and upper insulation. I don’t know but I guess even alpine regions here don’t get to such low temps as North America and Europe?
Hi Jack, that’s all interesting. I still prefer a solid floor:) However it was interesting to read that a beetle wont reenter a hive after being chased through a screened bottom board.
The article really doesn’t address the issue of over wintering bees in a climate such as where Vino is.
My bees generally fix the issue of lid ventilation with propolis. The vinyl mat I use serves the purpose of an inner lid, except it has bee space all around it. I don’t have an issue of water condensation chilling the bees.
Even with a solid floor, I don’t use any beetle traps.
Anyway the good news is that Vino has more packages of bees arriving in the coming weeks. Russian Nucs.
the commercial beekeepers here in SA I have seen use solid floors like you Jeff- it’s clear they work well. The beekeeper that supplied us with some nucs also used the vinyl mat covers on the top of the bars. One thing I noticed was that most hives here have roofs with a few inches of space above the bars- enough room for the bees to build comb in the roof- whereas the flow type hives only have a 1/2 or 1/4 inch beespace between the top of the bars and the inner cover.
I can imagine if it was minus whatever degrees- feet of snow- the bees would have a hard time keeping that constant cold from creeping in. I sure am glad to live in a Mediterranean climate when it comes to beekeeping.
Hi JeffH,
You are correct that there was no insulation on the bottom of the hive. Just the coreflute. There was not a suffocation problem because the snow never got deep enough to even reach the bottom board this winter. The lower entrance was open about 3" and I had the vivaldi board on top packed with burlap. There was air flow through the hive. When I did the check of the bees in December, the burlap was dry. The inner surface of the lid was totally dry. No signs of moisture or mildew anywhere.
I insulated the top and three sides, leaving the South side open to the sun (In the Northern Hemisphere, hives face South) I chose that insulation based on my local mentor who does basically the same system. The only difference is that he does not first wrap his hives with tar paper. I put the tar paper on as a secondary wind break because my hives are in the middle of a field. Also, the black paper absorbs more sunlight/heat on the exposed side to theoretically help warm the hive.
The bees were exploding, several frames of brood and laying queen in the last week of October. I was feeding fondant because they did not have a ton of food stored and with the amount of bees in the hive, I was worried they would run out of food. They were storing fondant and buzzing away as late as December 30. Then the cold snap hit. I didn’t open the hive for the month of January and the first 40+ºF (4ºC) day we got in February, I went up to have a look. That was February 18. The Flow Hive was gone.
During the search for the queen, I did see a fair amount of varroa (I picked through the bees close up for 45 minutes) but not an alarming amount. If this helps in any diagnosis, the thing I did notice was that the bees were very evenly distributed (dead) on the bottom screen. There’s wasn’t a deep pile near the entrance/exit, but a layer across the whole board. It seemed to me by the way the were dispersed that they died quickly, like there was a deep freeze and they all just fell off the frames?
Temps were in the -10s to -20 C at night for a couple weeks in January (not counting the wind chill.) Not super cold for bees from what I’ve read, but probably cold enough to chill a small cluster if they were already weakened by some other disease.
Saddest thing was all the honey stores left behind. They worked so hard all year!
I’ve ordered two new Russian Nucs for this season. They’re RHBA certified and locally bred just an hour from my house, so they are from my climate. I’m looking forward to getting to know some new bees.
Hi Vino, it’s sad to see all those dead bees. I’m wondering how you would go during winter if you doubled up the insulation, including the floor. Instead of having a 3" entrance facing out, you had a slightly wider entrance facing downwards. That way the whole hive is doubly insulated except for the downward facing entrance that will be out of the wind.
One bloke on the forum came up with what I thought was a brilliant idea. @Jape suggested using low wattage heat mats. That may require you to move the hives closer to the house, if you did move the bees closer to the house, why not place them in a nice cosy spot?
Also sorry for your loss vino.
Concerning jape’s idea about heat mats- I looked into that concept myself. I thought about a solar set up- using a small panel, possibly a battery- and these very cheap low voltage heat panels:
http://m.ebay.com/itm/141677815322?_mwBanner=1
Seems like you could affix them to some type of heat-sink material in the floor of the hive to just add a bit of warmth for the bees comfort?
Yes for sure Jack. Anything that will help the bees maintain a warm environment would have to be of benefit to the bees. I always had the impression that as long as the bees had honey or syrup, they would be ok until the honey or syrup ran out. Maybe if it’s just too cold, they cant generate enough heat fast enough.
@JeffH Funny you suggested heat mats… My mentor uses thin seed starting heat mats on the back wall of his hives. He puts the mats on the outside between the wooden box and the insulation. They’re thermostat controlled and won’t go on unless temps go below freezing. He basically never loses hives. My problem was that my hives are not near a power source so I couldn’t get that system together for this winter. I only saw his setup late in the year last fall. So I’ve just started reading about a solar concept like @Semaphore mentioned! That would be my only option.
I’d need a solar panel, a couple car batteries and an inverter. These are the mats: https://www.amazon.com/dp/B01N3XL3X1/
It would be quite an array, but possibly a real life saver.
One other thing I need to mention is that I get repeated comments on my videos that go something like this:
“Bees don’t die from cold. The can survive -40º temperature. You should not insulate the hive. You used too much insulation.” And on and on…
I have a feeling most people saying this live in an area that does not have below freezing weather for 4-5 months straight. And if they do, they probably have really established hives with high populations of bees. I just can’t fathom NOT doing some sort of insulation. Especially on a weaker hive. But these comments I get make me have some doubt… Maybe I did over-insulate? Did I do something wrong?
I’m admittedly a beginner and this was my first winter, but going by my mentor’s advice, he uses rigid foam insulation and heat mats on his hives and he does not lose hives. So there is a good precedent for insulating in my neighborhood. My instincts tell me to insulate more, but definitely make sure there is adequate ventilation (which I believe I did already.)
It seems to me that in those kind of freezing conditions- any help- whether it be insulation or additional heating must only be a good thing. assuming ventilation is OK. We know bees need to maintain a stable temp around 36c- it’s a long way from there to -10c.
Initially I just assumed bees raise the temp in the hive from their body warmth- it was only after a while I remembered they are cold blooded insects. They raise the temp through friction- supposedly by waggling their heads around. I am guessing there is only so much they can do- and if the hive is constantly losing heat to the outside they simply cannot cope even if they have ample stores. Most standard hives are only 3/4 inch to an inch thick- I am guessing the average tree or hollow would have more insulation value than that.
A human can eek out a long dark winter in a poorly insulated cabin- freezing their arse off- it doesn’t mean they would enjoy it! I think if I was a bee- in a hive in the middle of winter- I for one would enjoy a heated mat.
Hey Jim, really sorry to hear about your hive. Glad you’re trying again with new nucs. My one colony died this winter too, but more likely because of varroa-borne disease or weakness.
As for your YouTube commenters, I’ve read similar statements about bees not needing insulation, but one’s overwintering strategies are so particular to one’s situation. Bottom line for me is that a tree hollow or wall cavity, where bee colonies will often make a home in northern USA, are far cozier than a Langstroth box! So I feel that beekeepers like you & I would be foolish not to insulate.
Heat mats seem worth a try for next time - please keep us updated on your progress if you end up with a plan for using them. Thermostat control would be key for my area I think - yesterday it was 65F and Friday it’s supposed to be 40F, going down to 18 that night!
@Eva Sorry to hear about your colony. I hear you regarding temperature swings… We had 60ºF weather last Thursday and the bees were flying. On Saturday and Sunday it was -11ºF with the wind chill. A 70º swing in 48 hours. Now we’re back up in the 40ºs and 50ºs this week. I am going to be researching heat mats this season and will be sure to make a video about whatever I decide on! And then I’ll deal with the insulation haters.
Hi Jim, sorry for forgetting your name. It sounds like what your mentor is doing is the way to go. Anyone who doesn’t lose hives in your climate will be worth following to the letter.
Jim, if you’re going to maintain just a few hives, what would be wrong with moving them really close to the house during the winter? Especially if you had a spot that was out of the cold wind. The lack of bee activity during that period would negate/reduce the possibility of people getting chased or stung. I have an observation hive right near my back door with up to 20 nuc hives just around the side of my house. The entrances all face the wall.
Anyway that’s a long way off. Good luck with your new colonies, cheers for now.
I imagine I have a similar climate in Michigan. At least half the people here do insulate their hives with a bee cozy or insulation like Vino. It is also common to push your hives together and put the insulation around the whole thing. I remember reading some evidence, however, that showed no difference with or without insulation (I can’t seem to find it but if someone has it?) The bees do not actually heat the hive. They only heat the cluster. I would recommend watching Michael Palmer on youtube. He has pretty bad winters and travels the country giving talks on overwintering hives and nucs. He gave a talk at our local bee school a few weeks ago.
I don’t think his bees died from cold (not directly) or suffocation. His cluster dwindled to the point that they were not able to warm themselves. The most common cause in our area is mites. The mites allow viruses to get by the bee’s natural defenses and will result in unhealthy bees. Bees that you need to live for 4-5 months rather than 6 weeks need to be healthy. There is also some research showing that mites feed on the bees vitellogenin which would also explain winter loss (as this is what allows them to survive the winter.) The other theory would be queen loss in the late fall. It looked like he may have had a virgin queen on the bottom board. Many people here use screened bottom boards over the winter and don’t have an issue. Probably doesn’t make a difference one way or the other.
I’m interested in how the Russian’s do. Bee’s that can deal with varroa are our future.
Jeff, I’m jealous that you don’t’ have to worry about winters or mites!
-Mike
G’day Mike, the main problem down here is SHB. They have driven a lot of people away from beekeeping & causes a lot of anxiety. While over-wintering & mites would probably be the main topics of discussion at any club meeting up your way, SHB would be the main topic of discussion in a lot of areas down my way.
Guess there’s no free lunch. 
Hi Mike, no that’s right, I agree. My strategy for SHB where I don’t use any traps is to keep all the brood combs predominantly worker comb. I guess that would be a good strategy up your way also.
A very interesting discussion on overwintering and insulation. I am a newbie and will be getting my first package of bees in April from a local source. I live in the Kansas City area. Our Winters can be cold, but not near as cold as Michigan or Vermont. We also don’t have the prolonged cold spells. As I look ahead to next Winter with a hive entering its first winter should I insulate my hive? If so when do you put the insulation on and then take it off? Do you base it on the overnight low temperatures or the daytime highs? You talk about adequate ventilation; is that built in with the Flow Hive?
Brick
Hi Brick, you can insulate your hive year-round if you like. Some folks are using poly hives which gives permanent insulation. As far as ventilation goes, I believe a good size entrance is all the ventilation a hive requires. The bees will do the rest. I like an entrance to be wide enough so that the bees can draw air in one side & exhale it out the other side.