Surprising dead-out

[boywonder]

Hi all. So: all (20 or so) colonies I run went into winter with extremely generous stores, and having had an Autumn treatment (either MAQS or Apilife VAR). They are a mix of poly and cedar hives. On Jan 2nd, all were flying, and all were hefted. Though a couple were light-ish (to the extent that I gave one some fondant), I had no reason to expect any to fail to get through to March. I only cracked a couple of crown boards, but where I did (it must have been about 10 degrees), I saw large colonies; the ones in cedar in loose cluster - the ones in poly not in cluster at all.
.
Colony sizes were indicative of continued brooding through much of the winter... especially in the poly - which was pretty much as expected.

Since then, to my mind we've had a lot of rain, but relatively mild temperatures. I was therefore keen to again heft a couple of the lighter hives at the weekend, but was not expecting any dramas.

However, on lifting one of the brood boxes off the floor, I saw a disconcerting pile of dead bees, so opened the hive, to discover a dead-out.

On one level, it just looks like classic isolation starvation - but, as I say, I can't think these will have been in cluster for any length of time in January.

There was a half-decent amount of food across the whole hive, and in direct contact with the cluster of bees. That said, there were a large number of bees with heads in cells, and on one comb, they had chomped to the top corner. Other bees had just perished on the face of the comb, looking like they were in suspended animation. I have never seen this before.

I could not locate the corpse of a Queen.

There were no outward signs of disease (e.g. dysentery) - though they were on old comb, desperately in need of changing.

Lots of thoughts occur to me - e.g maybe that they died in the especially cold snap in December, and the traffic I saw in early January was robbing (?)

Maybe they were queenless ? A total lack of brood, relatively small number of bees, and lack of a Q cadaver might corroborate this ?.... though would not in itself cause the demise. Hmmmm.

I guess I'm going to get told that it's just one of those things.... but I would be interested to know if there are any other thoughts on causality, based on what I describe above, and the attached pictures. Please don't cane me for the state of the comb.

If this were March and/or we'd had an extremely long/harsh cold snap, I'd just write it off, and move on..... I don't lose many colonies; However, I've never have one succumb so early, let alone one I believe was so healthy (?) and well provisioned/insulated at the start of winter.

 

[boywonder]

Actually, there is the odd cell with what appears to be capped, ostensibly drone brood (? .... so potentially a queenless colony with laying workers ?? - maybe the MAQS did for her ???)

 

[Newbeeneil]

Hi all. So: all (20 or so) colonies I run went into winter with extremely generous stores, and having had an Autumn treatment (either MAQS or Apilife VAR). They are a mix of poly and cedar hives. On Jan 2nd, all were flying, and all were hefted. Though a couple were light-ish (to the extent that I gave one some fondant), I had no reason to expect any to fail to get through to March. I only cracked a couple of crown boards, but where I did (it must have been about 10 degrees), I saw large colonies; the ones in cedar in loose cluster - the ones in poly not in cluster at all.
.
Colony sizes were indicative of continued brooding through much of the winter... especially in the poly - which was pretty much as expected.

Since then, to my mind we've had a lot of rain, but relatively mild temperatures. I was therefore keen to again heft a couple of the lighter hives at the weekend, but was not expecting any dramas.

However, on lifting one of the brood boxes off the floor, I saw a disconcerting pile of dead bees, so opened the hive, to discover a dead-out.

On one level, it just looks like classic isolation starvation - but, as I say, I can't think these will have been in cluster for any length of time in January.

There was a half-decent amount of food across the whole hive, and in direct contact with the cluster of bees. That said, there were a large number of bees with heads in cells, and on one comb, they had chomped to the top corner. Other bees had just perished on the face of the comb, looking like they were in suspended animation. I have never seen this before.

I could not locate the corpse of a Queen.

There were no outward signs of disease (e.g. dysentery) - though they were on old comb, desperately in need of changing.

Lots of thoughts occur to me - e.g maybe that they died in the especially cold snap in December, and the traffic I saw in early January was robbing (?)

Maybe they were queenless ? A total lack of brood, relatively small number of bees, and lack of a Q cadaver might corroborate this ?.... though would not in itself cause the demise. Hmmmm.

I guess I'm going to get told that it's just one of those things.... but I would be interested to know if there are any other thoughts on causality, based on what I describe above, and the attached pictures. Please don't cane me for the state of the comb.

If this were March and/or we'd had an extremely long/harsh cold snap, I'd just write it off, and move on..... I don't lose many colonies; However, I've never have one succumb so early, let alone one I believe was so healthy (?) and well provisioned/insulated at the start of winter.

I have had two hives with very similar stories and their demise is a complete mystery.
Loads of stores and bees with there heads in the cells right next to cells with stores in.
As with you the hives were well populated, confirmed by a substantial pile of corpses on the mesh floor.
Varrorsis was my only conclusion but like you mine were all treated end of August with Apilife and dribble with OA in December.
Another beekeeping mystery?

 

[Swarm]

Second photo, top right corner by the top bar. Those wings look long for a worker.

 

[boywonder]

Another beekeeping mystery?

Indeed, I think so. I've had a lot more of these 'mysteries' in the last year.

... Just when you think your levels of experience and competence are such that you can understand "why" things are as they are ... Mother Nature just ups the ante, and gently reminds that, well...as per this clip

 

[jeff33]

Looking at the amount of bees on the landing board, it was a small cluster. Not sure when you opened them last but it could have been a failing queen which didn't produce enough winter bees to see them through. It usually goes pearshaped after that.

 

[ericbeaumont]

Evidence of attempts to uncap sealed brood, suggestive of high varroa level.
Looks like a patch of eggs in the third photo, below the stores.

Declining nest was probably the tipping point, beyond which the cluster could not maintain temperature. Varroa has played a part: although the colony was treated in September (?) continual autumn brood would have raised varroa levels (doubling every three weeks) by year end. Perhaps the queen was superseded poorly last year: few drones in there, which bees keep late if supersedure is on.

Not a mystery, but a combination of natural factors.

 

[Sting101]

I’m quite a newby but your photos seem to show a lot of drone brood in worker cells, so either the queen died and workers laying or an infertile queen. But like I say I am a newbee

 

[jenkinsbrynmair]

I think you answered your own question. lack of brood and not many bees - queen failure and the subsequent colony dwindle

That said, there were a large number of bees with heads in cells,

sometimes happens when the cluster gets so small they can't keep warm so duck into vacant cells to warm themselves

 

[jeff33]

I think you answered your own question. lack of brood and not many bees - queen failure and the subsequent colony dwindle

sometimes happens when the cluster gets so small they can't keep warm so duck into vacant cells to warm themselves

They must have been made aware of energy prices hike and decided it was better to die off than heat the cluster properly.

 

[pargyle]

I think you answered your own question. lack of brood and not many bees - queen failure and the subsequent colony dwindle

sometimes happens when the cluster gets so small they can't keep warm so duck into vacant cells to warm themselves

Plus ... the remaining capped cells in photo two have perforations in the caps - usually associated with varroa - also too few bees to clean the cells out is an indication of a weak colony. JBM and EricB are on the money - queen failure and colony probably weakened by varroa.

 

[rdartington]

I have had two hives with very similar stories and their demise is a complete mystery.
Loads of stores and bees with there heads in the cells right next to cells with stores in.
As with you the hives were well populated, confirmed by a substantial pile of corpses on the mesh floor.
Varrorsis was my only conclusion but like you mine were all treated end of August with Apilife and dribble with OA in December.
Another beekeeping mystery?

I have had exactly the same experience - 18 hives into winter, all treated for varroa by oxalic vaporisation which showed very few mites drop after treatment, so low infestation - all very heavy with left-on honey, no sugar feeds - first week in Jan no flying from 3 hives, opened and piles of dead bees on floor, few dead bees left on comb! Never known this before.
Now I see from this post that this is happening elsewhere, I am guessing it could be a consequence of warm autumn weather, causing colony to continue to rear large amounts of summer foraging bees, that brought in the largest ivy crop I have ever known, rather than winter bees, and those foragers were now dying off leaving too few winter bess to form a large enough winter cluster.
But may have been just failing queens, failing in autumn to rear winter bees.
Anyway - ouch!

 

[JamezF]

As far as I'm aware they don't "rear summer bees" or "rear winter bees". They're just bees, at different stages of development as a result of the functions they've had to perform within the colony.

James

 

[Erichalfbee]

As far as I'm aware they don't "rear summer bees" or "rear winter bees". They're just bees, at different stages of development as a result of the functions they've had to perform within the colony.

James

Yes they differ physiologically but winter bees is a useful descriptor

 

[ericbeaumont]

functions they've had to perform

Rather, the functions the winter bees are about to perform, which suggests there is a difference in manufacture.

 

[jenkinsbrynmair]

it could be a consequence of warm autumn weather, causing colony to continue to rear large amounts of summer foraging bees, that brought in the largest ivy crop I have ever known, rather than winter bees,

bit of a nonsense really - if they were foraging for longer, then the queens would have been laying for longer, thus younger bees going into winter, and later than usual, so at this point in the winter, if anything, they should be stronger.

 

[Ian123]

bit of a nonsense really - if they were foraging for longer, then the queens would have been laying for longer, thus younger bees going into winter, and later than usual, so at this point in the witer, if anything, they should be stronger.

Yes definitely should have been stronger, there’s a distinct difference in colony size in Spring between those that have access to late forage and those that don’t.

 

[Karsal]

I'm of the opinion that some colonies cannot survive over a wet, cold and windy winter due to them having an open mesh floor. I've tried numerous occasions to catch a swarm in summer with hives with closed floors and hives with OMF's. Never caught one yet in a hive with an OMF.
Small picture of a nucleus from a few years ago confirmed my thoughts. They didn't propolise this OMF for nothing.

 

[jenkinsbrynmair]

I'm of the opinion that some colonies cannot survive over a wet, cold and windy winter due to them having an open mesh floor.

strange, the majority of my colonies are on OMF, many kept at fairly high altitudes and they manage just fine. And yes, I've also had swarms move in to hives with mesh floors.

 

[JamezF]

Rather, the functions the winter bees are about to perform, which suggests there is a difference in manufacture.

That's not how I understand it to work, in part because they don't know what tasks they're going to need to perform or when.

As I understand it, the process is initially driven by the amount of brood being reared because that in turn affects the amount of vitellogenin stored in the fat bodies of each bee. Rearing brood uses up vitellogenin which, if not replaced sufficiently quickly, allows juvenile hormone to "age" the bee and it moves on to the next phase of its development ("summer bees"). When vitellogenin stores are high because there's less brood to feed it inhibits production of juvenile hormone, so the bee ages more slowly ("winter bees") allowing them to continue to perform all those functions necessary for raising brood for the start of the next season. So "winter bees" are just the same as "summer bees", but part of their early development has been stretched out in response to reducing brood numbers.

It occurs to me that the same effect might be beneficial during swarming to allow nurse bees to span a brood break when the they would develop into foragers quite quickly if there hadn't been a swarm. I've no idea if that's correct or not though.

James