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Thread: Colony losses

  1. #1
    Administrator gavin's Avatar
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    Default Colony losses

    Hello All

    I think that Eric in his new blog was implying that we're ignoring a big issue or two. Not quite fair as we have debated winter losses here, but it does seem like a good time to revisit it now. For me winter losses are not necessarily bad. It removes maladapted genetics, frees equipment for the wonderful season to come () and more than anything teaches us important lessons about our beekeeping. My beekeeping is just as imperfect as the next man's (or woman's), but I am trying to learn from my mistakes.

    So, winter losses. From what I hear in the E of Scotland it may be a bad year for some, but an average year for others. There has been some informed speculation that massive losses among a few large-scale beekeepers in the east might have been Varroa-related.

    My summary: Went into winter with 6, coming out with only two. One more is alive but I think that it is queenless.

    Losses: one late last year, one early this year after the oxalic dribble, one in the last 2 weeks, one still alive but apparently queenless.

    What happened? Not one of them had any new brood. I think that the queen shut down last autumn in at least two and never started up again. Not a good move. The one I've just lost looks like isolation starvation with stores a short distance from the cluster, and there were no eggs or brood at all. Was it a queen problem? On the other hand it had a small patch of brood on 21 March, so how is it broodless now?

    What could I have done? I'm really not sure. I could and should have fed them better and earlier last autumn, but all of them left stores behind and may have failed anyway. Should I have fed them at queen-rearing time last year when the weather was awful? Maybe. Was I risking their later health by letting Varroa rip through them early last summer? Maybe, but then I know someone else who didn't treat for Varroa and had better survival. Should I have done something about their general ill-health last summer (chalkbrood, sac brood). Probably - Bailey comb change? Perhaps I need to raise more queens and selfishly keep spares for myself rather than give them away to beginners?

    Was it all queen failure? Maybe not this last one. I had the trouble described in my blog with entrance blocks moving. Linchpin suggested blue tits, but there was also mouse activity in some (worst in my strongest survivor in fact). Did mice kill the queen in the one I've just lost? Or blue tits? There is a lesson there, in that last winter the perforated metal mouse guards worked reasonably well, and this winter the wooden blocks on the new mesh floors didn't. I need to find a way to keep the guards in place. Maybe I should be insulating the top of the hive too.

    Why are queens failing? I'd really like to know. Most likely seems the poor weather last summer, leading to poorly nourished queens, poorly mated queens and maybe sub-standard drones too. There are other possibilities, such as more or different pesticides in the environment than previously. Is that imidacloprid-treated oilseed rape to blame? It *could* be as my queens would have been raised on the stuff last year, but let's hear what everyone else has to say first. If people are seeing queen failures only or mainly when they have been exposed to rape or some other source of insecticide then that might tell us something. Alternatively, on other fora last year people were describing similar problems away from arable agriculture. A beekeeper I know in England reports queen problems in the last few summers which disappear in batches raised late in the summer when the weather improved, so I'm keeping an open mind for now. Maybe people on this list could add to this.

    Did beekeeper-applied chemicals contribute? I haven't used fluvalinate for years and always used it according to the label. Oxalic dribbling might have hastened the death of one colony, but I think that it was doomed anyway. Apiguard in late summer should have improved the bees' health and helped winter survival. I did add thymol to the syrup in the autumn, but I doubt that could be a problem.

    What about autumn feed and stores? My strongest was wintered wholely on heather honey. My other survivor was fed syrup last autumn while others were at the heather, and its stores were topped up with a super of crystalised rape honey. It also had access to a small ivy flow in the late autumn, as did all the colonies.

    So there we are. Could do better, should do better, but I'm thinking that queens problems are my main issue and I'm not ready (yet) to blame anything for this other than the poor weather at queen raising and mating time.

    Anyone else? A summary of losses/survival and why you think your losses happened?

    best wishes

    Gavin

    Afterthought: the one I've just lost was a 5-framer last autumn in which I never used dummy boards to close down the space (bad me). Nice solid frames of stores each side of the neat brood nest, so they'd be OK, wouldn't they?! They survived into late March, but maybe that last cold snap did for them. In which case I'm annoyed with myself as I could have done more for them. It was a swarm last summer from 10 miles away and looked rather Amm-ish, so I'd have liked to have kept them. Must have a rummage on the floor on Saturday and see if I can find the queen.

  2. #2
    Senior Member Jon's Avatar
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    I lost a colony last September which in part was my own fault.
    It was one of the strongest colonies in the apiary and had two supers half full of honey at the start of August.
    It then rained for three weeks.
    I did a colony inspection some time around the end of August and there was not a pick of food left in the hive.
    hungry bees were starting to fall off the combs. I put a feeder on straight away and they took down kilos of sugar in strong syrup.
    In spite of this, the colony had dwindled to a couple of frames of bees by the end of September.
    I reckon that it succumbed to a stress induced ailment brought on by reaching starvation point, possibly one of the nosemas.
    The other possibility is a duff queen as this hive had tried to supersede in early July even though the queen had only been laying for 6 weeks.
    Last summer I noticed a lot of the queen problems Roger Patterson has been highlighting on the BBKA site.
    Were I a gambling man, I would bet on it being something to do with Nosema rather than our old friend Imidacloprid.

    That left me with 13 colonies going into winter, 9 decent ones and 4 smallish nucs which I had made up from extra supersedure cells in August.
    I fed them about 100k of sugar syrup in the autumn.
    I had actually contemplated skipping varroa treatment as I had hardly seen a mite all year either on the trays or in drone brood.
    But then mites started to appear in numbers on the trays in September so I treated.
    Mite numbers double every month, and late summer is when you can see a dramatic increase.
    I treated with Apiguard starting mid September, which is really a bit late.
    On 22 Dec. I treated all with Oxalic acid trickle.

    I was able to check between 17-19 March and all colonies were alive but one nuc was missing a queen. Another nuc had a queen with about half a frame of bees so I combined them. Another queenright nuc had dwindled to the point where I was able to tip them into an Apidea. This one is in my garden shed and the queen is laying. Another colony which was very strong in the autumn has dwindled to a frame of bees but has a laying queen. The rest of them are fine with 2-4 frames of brood.
    I checked a couple this afternoon and the strongest would have no more than 6-7 seams of bees.
    The reason the nucs came out of winter so weak is that they went into winter with only 2-3 seams of bees.
    I really should have combined some in the Autumn but they had brand new queens and I wanted a chance to evaluate them.

    So the state of play is I have 10 viable colonies and a couple of spare queens. I can use these to make nucs in early May if they are still alive.

    Jon
    Last edited by Jon; 07-04-2010 at 06:55 PM.

  3. #3
    Administrator gavin's Avatar
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    Quote Originally Posted by Jon View Post
    I reckon that it succumbed to a stress induced ailment brought on by reaching starvation point, possibly one of the nosemas.
    Interesting. My first one to go was on the point of starvation in August - bees in slow motion.

    Quote Originally Posted by Jon View Post
    So the state of play is I have 10 viable colonies and a couple of spare queens. I can use these to make nucs in early May if they are still alive.
    Do you sell bees across the Irish Sea?!

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    We went into winter with three, two technically belonging to my friend. 1 was a swarm that gave us nothing but trouble all year superseding queen after queen and as of last week it finally succumbed. His other colony is currently hanging on by a thread but we're only talking about 1-2 frames of bees at the moment. We were talking about this today to see if there was anything definite that we could out our fingers on as to what went wrong. There was a reasonable amount of chalkbrood in the colony throughout the summer, but it was numerically by far the strongest of the three colonies.

    Mine went into winter preparations reasonably strong across 9 frames in total, including stores. They'd swarmed reasonably late in July and the new queen came into lay sometime in August. As the mite count had been low all year I was questioning whether to treat with Apiguard at all, but did eventually in Mid September. I gave them the first super of stores, scoring the cappings and moving the super under the brood and letting them move the stores up before removing the super completely, this still left me with 2 frames unused in the brood area and I topped up with a small amount of syrup.

    Since February I've topped the colony up with fondant and late march I gave them a litre of 1:1 syrup

    I deliberately didn't treat with OA over winter for a number of reasons, first I guess is that I didn't like the idea of pouring acid over the bees. While I hesitate to invoke the term "Natural Beekeeping", I do want to try and limit the amount of treatments applied to them as much as possible whilst still balancing that with the fact that a loss for me at the moment is 100% losses. Since October I've cracked the crown board twice. Once to get some idea of how strong they were, the last time to do a "half inspection" and apply an apiguard treatment.

    This is about the same point that I took them over last year and they look far stronger to me now than I recall them being back then, but that might just be me.

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    Administrator gavin's Avatar
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    Superceding queens and spring dwindling .... worth checking for Nosema? [Thinks: I ought to check my own as well!]

    Quote Originally Posted by Nellie View Post
    While I hesitate to invoke the term "Natural Beekeeping", ....
    How very wise!

    G.

  6. #6

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    Lost one this winter - isolation starvation. Foul tempered colony which I shook swarmed last Spring as a varroa treatment. They built up strongly again through last summer. Plenty of stores in brood frames and a super which I left them going into winter. Then I got swine flu and pneumonia and had a long stay in hossie so they never got their winter oxalic trickle. A very small cluster of dead bees left when I opened it in March.

    This winter I might be tempted to try oxalic vapourisation as an alternative to breaking open the hive in midwinter. I know it presents a few hazards but if we have another winter like this one they're going to need to conserve their heat!

    Gerry

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    Quote Originally Posted by gavin View Post
    Superceding queens and spring dwindling .... worth checking for Nosema? [Thinks: I ought to check my own as well!]



    How very wise!

    G.
    Did cross my mind to suggest that he gets some samples off both colonies so we can get a better idea of what might have gone on. After I'd put the phone down, naturally.

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    Finaly managed to get into my one remaining colony yesterday,two seams of brood - the rest of the hive chock-a-block with sealed stores,so much so that the Q had no space to lay.Stuck another brood box and frames on top so with a bit of luck and fine weather the colony will move up.I lost my other colony - similar in appearance to Gavins - small area of brood,small cluster of bees and isolation starving despite loads of stores.Possibly Nosema causing dwindle together with the cold/warm/very cold weather we've had.I had lost 8 colonies the previous winter I think possibly from a neuc that was infected with nosema cerenia so excessive dwindling but no faceal smears in the hives.The alternative reason is the possibility that my bees were robbing .My neighbour had 70 colonies scattered about the district and lost 60 of them in the previous winter -( I dont like to ask him what he is down to at this moment.) So robbing his hives is a distinct possibility.I want very much to keep the existing colony as they are as black as soot and quite possibly have a lot of AMM also seem very healthy.We're away from the district for a week (would co-incide with the best forcast we've had in ages) so hope to sort things out more when we return.I need to split this colony a couple of times and concentrate on bee production not honey production.

    Another strange thing about the colony that died out was the Q didn't lay any drone brood.I looked on a regular basis but didn't spot a single drone cell with eggs,larvae or cappings.I saw a couple of drones in the hive but possibly from outwith this colony - I don't know if anyone else has experienced this ??

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    Administrator gavin's Avatar
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    Thanks Grizzly (and all, but keep them coming)

    It strikes me that we (me included) could be a lot better at diagnosing the causes of these losses. I'll have a better look at my last one at the weekend and see what I can make of it.

    I had thought that the presence of brood would be a give-away in that no brood equals queen problems, but having now seen one that did have a laying queen then a couple of weeks later had no brood in a dead colony maybe I was kidding myself. A colony in trouble probably stops brood raising and might let the remaining brood hatch.

    Someone (maybe the diseases guy for a national beekeeping association, with help from those who really know) should write a guide to diagnosing losses.

    Grizzly: there are some stocks that seem reluctant to make drones, then really go for it at the right time. Most stocks will not make drones when the colony is small and the queen young, such as when building up from a small nuc, and I've seen them go through the summer without making drone cells.

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    Quote Originally Posted by gavin View Post
    Someone (maybe the diseases guy for a national beekeeping association, with help from those who really know) should write a guide to diagnosing losses.
    Good idea, Gavin. I've heard the SBA guy isn't bad

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