Fourth post mortem

One of my students contacted me earlier in the week to say he’d noticed a reduction in flying and a lot of dead bees outside the entrance and behind the mouse guard. They had been foraging and bringing in pollen for the last few weeks which is usually a good sign that the colony is getting ready for spring build up. Bruce’s colony was a swarm from last summer and had done well (although not anything extraordinary) and were only covering about 6 frames. As they were in a National, I suggested he made a cover to go over the hive to protect them in the winter, and being a keen woodworker, he built a wooden “shell” which sat over the hive to keep the weather off. Their garden and surrounds are well provisioned with forage, and following my advice, he’d planted crocus and some new native trees to provide additional resources, showing how having a hive can really encourage good husbandry and engagement with our gardens.

As with the other colonies which have died, there were no honey stores in the hive, and a few cells of pollen. We have had a succession of storms through February, and last weekend we had Storm Jorge which although milder and less destructive than its predecessors, still brought strong winds and rain. There is plenty of blossom around now, but of course even if it is not technically too wet and cold for the bees to fly, they are reluctant to take off when it’s breezy, as shown in this study at LASI, part of Sussex University.

There were Varroa mites – a few on the board but some on the bees too, and a number of bees with stunted abdomens and deformed wings. The queen was quite small, but there had been brood. This time last year I was checking my bees as it had been so warm and mild through February, plus we had had a good autumn with the bee flying well in to November; this year will have challenged many small colonies as well as other pollinator species. I suspect the bees would have made it if last month hadn’t been quite so stormy. Remember the bees in the colony now are those which hatched in the autumn, and their strength and vitality will enable the colony to build up in spring. They can’t survive if they are tired and weak due to damp, cold, lack of food, and Varroa. When Bruce had contacted me, I said he could try sprinkling some icing sugar on to the crown board as an emergency measure but of course it was too late for this to make a difference.

What can we learn from this? If possible, unite colonies in the late summer so that they have a larger mass of bees to maintain core temperature. Insulate early in the autumn to preserve precious stores. If you have more than one colony and can spare a frame or two of honey to boost a smaller one, do so. If your bees are only covering 6 frames, consider transferring them to a nuc box so they can overwinter in a smaller space and conserve heat.

Bear in mind that all the above suggestions are easily considered in hindsight. There are risks in uniting colonies in the autumn unless one is definitely queenless, and moving them to a different box needs to be done with care so that the queen isn’t damaged. Feeding is of course an option, but one needs a crystal ball to determine if that is going to absolutely be necessary, and as I have said countless times, a more sustainable approach is to ensure your bees have sufficient stores/bees/insulation as the sticking plaster of sugar syrup is not really a long term solution.

The drawn comb will be used top bait Bruce’s two hives, so we now have to wait and see how the remaining colonies we have in our apiaries and environs respond to the spring weather, if and when it finally arrives…

2 Replies to “Fourth post mortem”

  1. I just had my strongest colony die in a matter of days. It’s such a frustrating mystery! They had no issue with mites or anything, in fact it was the most hygienic β€˜dead’ hive I’ve ever seen. There were thousands of dead bees on the bottom of the hive, 3 combs of beautifully arranged capped brood and larvae, 10 drawn combs in all. After thinking on it for days the only theory I can come up with is they lost their foragers one day when the temp dropped quickly, or from somebody spraying their fields or something. I’m in Texas, we’ve had a lot of β€˜weather whiplash’ going from high 70s down to 30s quickly (a lot of weather modification going on) so maybe that caught them off guard? Any thoughts?

    1. You make a really good point. I think at this time of year they are so stretched with their resources (bees/stores/brood) then there are probably lots of factors which at other times they would shrug off, but of course in the early spring they have a small population of old bees having to work really hard to maintain all aspects of hive life, and if even a few of them get knocked out by weather or pesticides, it must have a relatively high impact on the colony dynamics. We have had sudden hailstorms here, and torrential rain, and if bees are out in that because it had been sunny and warm until a few moments ago, they may well not make it back, or if they do they are cold and wet. Resilience and adaptability is going to be vital for bee colonies as we go on, given the fluctuations and weird weather we experience now.

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