A tale of two swarms

Or … why it’s good practice to clip the wing of the queen.

After a cool start to May it’s now (s)warmed up nicely. Colonies are piling in nectar, mainly from the OSR, and building up really strongly.

It’s at times like these that vigilance is needed. A skipped inspection, a missed queen cell, and the season can go from boom to bust as 75% of your workforce departs in a swarm.

Not the entire season … but certainly the first half of it.

All beekeepers lose swarms … but should try not to

Natural comb

Natural comb …

All beekeepers lose swarms.

At least, all honest ones do 😉

However, I can think of at least four reasons why it’s pretty shoddy beekeeping practice to repeatedly lose swarms 1.

  1. Beekeepers like bees, but some of the general public do not. Some are frightened of bees and a few risk a severe (or even fatal) anaphylactic reaction if stung. Beekeepers have a responsibility not to frighten or possibly endanger non-beekeepers.
  2. Most swarms do not survive. Studies of ‘wild’ bees have shown that swarming is an inherently risky business 2. The swarm needs to find a suitable new home and then collect sufficient nectar to draw enough comb to build up the colony and store food for the  winter. The vagaries of the weather, forage availability and disease ensure that most swarms do not overwinter successfully.
  3. Swarms have a high Varroa load. The mites transfer a heady mix of unpleasant viruses within the colony, shortening the lives of the overwintering bees. With high virus and mite loads the swarm colony is likely to be robbed by nearby strong colonies. This effectively transfers the mites and viruses to nearby managed colonies, so risking their survival.
  4. The swarmed colony is left with a new virgin queen. She has to mate successfully to ensure the continued survival of the colony. Again, the vagaries of the weather mean that this isn’t certain.

And you get less honey 🙁

Regular inspections help prevent the loss of swarms. But it’s good to get all the help you can.

Here’s a brief account of two recent events that illustrate the differences between swarms from colonies with clipped queens or unclipped queens.

Swarm in an out apiary

I have an out apiary in a reasonably remote spot containing half a dozen colonies. I keep my poorly behaved bees there 🙂 There are other apiaries in the area as the forage is good.

I went to inspect the hives at the end of April. This was only the second inspection of the year. On arriving I found most colonies were very active, but one was suspiciously quiet.

Thirty metres away there was a swirling mass of bees settling in the low branches of a conifer.

My three initial thoughts were “Aren’t swarms a great sight?”“Dammit, they shouldn’t have swarmed!” and “Perfect timing, where’s the skep?”.

Skep and swarm

Skep and swarm

The skep was in the car. It usually lives there during the swarming season. The bees were spread over two or three branches, all drooping under the weight. After a bit of gardening I managed to drop the majority of the bees into the upturned skep 3.

I inverted the skep over a white sheet laid out on the grass and propped one side up using a bit of wood.

The air was full of bees. While I busied myself inspecting the lively (in more ways than one 😉 ) colonies, the swarm gradually started to settle into the skep.

Skep and swarm

Skep and swarm

There were lots of bees exposing the Nasonov’s gland at the end of the abdomen, fanning frantically at the entrance to the upturned skep. This is a pretty certain indication that I’d managed to get the queen into the skep.

Fanning bees

Fanning bees

An hour later I’d finished all but one inspection – the quiet colony – it was beginning to get cool and the light was fading.

I could no longer see eggs, not because there weren’t any but because I’m not an owl.

The swarm still needed to be hived so I left the quiet colony until the following day, wrapped the skep in the sheet and took it to another apiary.


And then the temperature plummeted. For the following week the daytime highs barely reached double figures. Nighttime temperatures were low single digit Centigrade.

The swarm would likely have perished and had a virgin queen emerged in the ‘quiet hive’ she’d have not got out to mate.

I didn’t look in another hive until the 7th, but when I did I got a surprise.

The ‘quiet hive’ contained a marked laying queen. I’d requeened this colony late in 2018 and my notes were a little, er, shambolic 🙁

I’d not recorded whether the queen was clipped and marked (the usual situation), marked only (not entirely unusual) or clipped only (not unknown!).

Whatever, they hadn’t swarmed after all 🙂

They were quiet because they had a high Varroa load with overt signs of DWV infection. Mite and virus levels in late September had been checked and confirmed to be very low. Presumably the mites had been acquired by drifting or robbing late in the season 4.

The hived swarm contained an unmarked laying queen and are lovely calm bees 🙂

A swarm in my home apiary

Fewer photos for this one as I didn’t have a camera with me …

I arrange my hives with the frames oriented ‘warm way’ 5 and inspect them standing behind the hive to avoid returning foragers.

Number 29, your time is up.

Number 29, your time is up.

Earlier this week I noticed a few bees flying under the DIY open mesh floor (OMF) from behind one hive. It’s not unusual to have bees at knee height during inspections but since all I was doing was dropping a nuc off in the apiary I didn’t give it much more thought.

Later in the week I returned to do the weekly inspection.

There were more bees going underneath the hive.

With a bit of effort I peered under the floor to find a 5cm deep slab of bees almost entirely filling the space under the OMF.

Better notes means you know what to expect

My notes were much more comprehensive this time 😉

I knew that the colony had a 2018 white marked and clipped queen.

I removed the supers (which were reassuringly heavy) and quickly inspected the brood box.

Lots of bees, lots of sealed brood, some late-stage larvae but no eggs.

In addition I could see two queen cells … one sealed and one about 3-4 days old, unsealed and with a fat larva sitting in a thick bed of Royal Jelly.

Don’t panic

It was pretty obvious what had happened.

The colony had swarmed 6 but the clipped queen, being unable to fly, had crashed to the ground in a very unregal manner, climbed back up the hive stand and sheltered under the OMF. The swarm had then clustered around her.

They had probably been there for a few days.

Another swarm hived

I placed a new floor and brood box next to the swarmed colony, with the entrance facing the ‘back’. I removed the swarmed brood box and, with a sharp shake, dumped the entire slab of swarmed bees from underneath the OMF into the new hive.

Before adding back all the brood frames I peered into the box as a tsunami of bees started moving from the floor up the side walls.

There! A white marked clipped queen 🙂

White clipped and marked queen returning to the colony

You’ll now have a better chance of finding and keeping her if they swarm.

It’s always reassuring to know where the queen is … and to have good enough notes to know what to look for 😉

I assembled and closed up the new hive and put the swarmed hive back in its place. I then carefully went through every frame checking for queen cells again.

There were only two. I destroyed the sealed cell. I didn’t know how old it was and couldn’t be certain it contained a developing queen.

In contrast, I could ‘age’ the unsealed cell (3-4 days) and knew it contained a larva and copious amounts of food.

I prefer to know when a queen emerges rather than save a few days by leaving the sealed cell. I only generally leave one cell to prevent casts being lost.

There were very young larvae in the colony. It is therefore possible the bees could generate more queen cells in the next day or so. Since I know when the queen will emerge I can check the colony before then and destroy any further cells they generate.

Two swarms, the same outcome … lessons learned

As far as this beekeeper (and I hope the bees 7) is concerned both swarms had a satisfactory outcome.

A number of lessons can be learned from events like these:

  • All beekeepers ‘lose’ swarms. Weather, work, emergencies and life generally can conspire to interrupt the 7 day inspection cycle. Sod’s Law dictates that when it does, the colony will swarm. I’m reasonably conscientious about inspections but I completely missed the signs the home apiary colony was about to swarm.
  • The weather can change suddenly. The swarm in the conifer would have probably perished from the cold in early May. If the weather had stayed warm the scout bees would have found a welcoming church tower or roof space to occupy in a day or so. In both cases the swarm would have been truly lost.
  • It’s always good to carry equipment to capture a swarm. A sheet and a skep, or a large nuc box. Secateurs make ‘gardening’ easier (mine are no longer AWOL). Spare equipment (hives) is essential during the swarm season.
  • An obviously smaller-than-expected colony and a nearby swarm may well be completely unrelated. Check why the colony is weak and take remedial action if needed (mine has Apivar strips in now).
  • Colonies near my out apiary appear to have high mite levels. Since that’s where the conifer swarm came from this also now has Apivar strips in.
  • When is a lost swarm not lost? When the queen is clipped. The queen cannot go far so neither can the swarm. If she returns to the hive stand or the underside of the floor, so will the swarm. If she perishes for some reason the swarm usually returns to the original hive.
  • You can keep bees without knowing where the queen is, but it’s easier if you do. Marking her helps find her, clipping her wing helps keep her there 8.
  • Similarly, knowing when the queen will emerge allows you to predict when she will be mated and start laying. You can avoid interrupting her returning from her mating flight and – before then – you can remove other queen cells to prevent the loss of a cast from a strong colony.
  • Good notes help. Keep them 😉

It’s relatively easy to find unmarked queens in smallish colonies early in the season. It’s a lot harder to find them in a strong colony in mid-May.

Mid-May ... 45,000 bees, 17 frames of brood, one queen ... now marked

Mid-May … 45,000 bees, 17 frames of brood, one queen … now marked and clipped

But it’s worth finding her, marking her and clipping one wing.

If you don’t the swarm you lose might really be lost 😉




  1. Perhaps unsurprisingly none of these are mentioned on the website of the Natural Beekeeping Trust … funny that.
  2. Thomas Seeley, inevitably … but I can’t find the reference at the moment.
  3. I had to break a few branches or twigs off and it was all a bit of a palaver … where were my secateurs?
  4. They hadn’t been treated with oxalic acid in midwinter.
  5. Parallel to the entrance.
  6. No sh1t Sherlock!
  7. But that would be anthropomorphic and if I’m not careful I’ll be naming the queens next.
  8. And I’ll deal with how to in the future.

17 thoughts on “A tale of two swarms

  1. Alan Forskitt

    HI, you refer to swarms as having a ‘high varroa load’. Would you explain this as I usually find the opposite, also, if the load was too high, then the colony would be weak end not be in a condition to swarm. However I would agree that a weakened and ‘dying ‘ colony might abscond and bring the mites to a managed hive or the managed hive robs out the weak infested hive. Thanks

    1. David Post author

      Hello Alan
      I’ve written about this previously. I guess I should have been a little more specific in the statement … swarms can have a high mite load and do have a proportionately higher load than would be expected based upon the standard partitioning of mites between capped and phoretic populations … but that’s a bit long-winded.
      When measured, about 25% of the mites leave with the swarm. If the swarms you see have low numbers of Varroa perhaps they originate from colonies with very low Varroa loads.
      Certainly if the colony has a very high Varroa load then it will be so weakened that it’s less likely to swarm.
      Thomas Seeley’s studies of bees in the Arnott Forest – which ‘tolerate’ Varroa – do so by swarming frequently, with lots of mites leaving with the swarm. This probably aids survival by sharing the pathogen load between the original colony and the swarm.
      Robbing of mite-weakened colonies is probably a major issue in late summer.

      1. alan forskitt

        Yes I agree with the way you have phrased this now. The mite drop will also seem high from a swarm as about 80% of the phoretic mites will have largely died off thorough old age before the first new brood cells are capped – given 3 days to build cell and 10 days to capping and the phoretic life expectancy of the mites being about 30 days in summer.
        These figures are from my memory of written facts and is also the basis of a forced brood break by splitting as a good varroa treatment.
        Seeleys studies of bees are among the best writings on bees in natural situations and give us a fantastic way to look at bees natural behaviours. Together with his observations in the Arnott forest they form a great way to develop a treatment free method of keeping bees. You may lose a little honey but you gain from increasing colonies and the knowledge that you are not pumping chemicals into the hives.



        1. David Post author

          Hi Alan
          I’m not sure how good the data is on phoretic mite life expectancy. It’s also clear that mites can survive for very much longer than 30 days (e.g. winter) and experience a lower attrition rate to the one you quote. What triggers this increased longevity? More vitellogenin in the diet? Something else? Although the former probably doesn’t apply to a swarm, it’s clear that Varroa can cope pretty well with swarming of their host species.
          I certainly agree that Seeley conducts some of the most elegant studies on natural bee colonies and populations. He also writes beautifully.

          1. alan forskitt

            Hi David, Yes, the figures were approx. 30 days in summer and 60 in winter which explains why the winter brood break in our winters does not fully eradicate the mites. With your comment on the vitagellin you may have inadvertently hit the nail on the head as the research which I read was definitely before Samuel Ramsey’s research into mites feeding on the fat bodies of bees but they also appear to feed this way in the summer. As a side issue, last year my queens were taking up to 39 days to start laying from their egg being laid as opposed to the more usual 28 to 30 and the weather was good all summer and the mite counts went very low after this. Maybe the bees are getting wise (I hope).Let’s see what happens this year.
            All food for thought,
            all the best, Alan

  2. Bee Man Bunty

    Unfortunately, I have not seen the queen since past 2 weeks, and now there are single and double eggs in empty cells, and colony is not so many compared to last season. Help! What shall I do? I only have 1 hive 🙁

    1. David Post author

      There’s not enough information in your question to be definitive …
      Has the colony already swarmed? That would explain low bee numbers. If there’s a new mated queen in the colony she will sometimes lay double eggs in cells for a few days.
      Alternatively, if the colony has been broodless for a long time there’s a chance you have laying workers. These are characterised by a random laying pattern with multiple eggs in each cell.
      Do you have a mentor or belong to a local association? If so, ask for some local help. Diagnosis over the internet (or phone) is always tricky … whatever NHS Direct would have us believe!
      Your final sentence demonstrates why it’s always good to have two hives. It’s about the same amount of work, but you can easily get a test frame to determine if one of the colonies is truly queenless.
      I hope things work out.

      1. Bee Man Bunty

        Thanks for your reply and advise, the colony has not swarmed, also the mentor who is local to me is never available therefore I am a self learner. I saw the queen about 3 weeks ago and the red dot marked on her had disappeared, therefore I marked her again (it was a clipped queen from last year) safely and put her back into the brood chamber. Now I did not see her majesty ever since. Shall I wait and see before I purchase a new queen? Yours Sincerely 2nd year bee keeper (and no honey as of yet 🙁

        Best Regards,

        1. David Post author

          It’s probably too soon for the colony to develop laying workers … is there sealed and open brood in the colony? Is the sealed brood all drone brood?

          If there is unsealed worker brood in the colony then the queen was there a week ago.
          If there’s not any sealed worker brood i.e. it has all emerged, then the Q last laid in the colony 3 weeks ago (because that’s how long it takes for workers to develop).

          You need to work out when she was last there (partly based upon when you last inspected and partly on the state of the colony … I’m assuming there was brood in all stages at the last inspection?) and then determine whether it’s worth it or wise to get a new queen. If the colony is queenright and you add a new queen there’s a chance both queens will perish while fighting it out.

          Far better to put a test frame of eggs (from your mentor … who isn’t a mentor if s/he is never available! Surely there someone else in your local association to ask?) in to determine whether the colony is queenless. This usually works within a couple of days unless you already have laying workers in the colony.

          If they draw queen cells on the test frame you can either wait for them to develop, or knock them back and add a purchased queen.


          1. Bee Man Bunty

            Hi David, thanks…I saw a load of sealed drone brood 3 weeks ago, but did not see any unsealed worker brood as of yet, I will check again on next inspection to find if queen is there. I was/am worried because I always saw the queen on every inspection since my 1st year. Anyway thanks for your advice, very helpful indeed.

            Best Regards.

          2. David Post author

            If you only saw sealed drone brood 3 weeks ago then there’s certainly a problem with the Q.
            Queens can be elusive, particularly as the colony size builds up as the season advances.
            I hope she turns up OK.

  3. Bee Man Bunty

    Hi David,

    The hive is certainly queen less now and a laying worker one too Fortunately a local Beekeeper has offered a frame of brood and eggs this week, the only concern I have is, can I put in a frame of brood from another hive while there are laying workers in my hive? Will this solve the issue I have? Or is my first hive doomed? Oh deary me!

    Many thanks.

    1. David Post author

      I’ve written about laying workers before. The pheromones from the open brood suppress egg laying by workers in the recipient hive. It does work, but you usually have to put several frames in over an extended period. I’ve always thought it was a waste of good brood, but I have a lot of colonies and so the loss of one isn’t a major problem. If I have to deal with laying workers I do it like this – combining shaking them out with a frame of eggs and young larvae.
      Good luck

  4. Bee Man Bunty

    Hi David,

    Thanks for the advice and I hope it works out for me, or else I guess I will start all over.

    Best Regards.

  5. Ian

    Hi David – what’s with all the wires? I assume it’s some sort of hive monitoring system. If it is, I’d love to hear what the data said whilst you were having all these shenanigans. I’d like to invest in this area, but unfortunately all the available systems are outside my budget at the moment – maybe next year.

    1. David Post author

      Hi Ian

      We have Arnia monitoring systems on some hives. We can record hive temperature, humidity, entrance activity, weight etc. We’re a long way off being confident with it yet and I’ll post something when we have more experience.

      Temperature and humidity monitoring is relatively trivial. I built a system that worked using an Arduino and some very inexpensive bits and pieces. Now I have 12V in the bee shed I should perhaps look at it again. The main problem is power to remote locations (which is where many apiaries are). Colony temperature allows you to determine whether they are rearing brood – useful for the midwinter treatment – and shows when a queen comes on to lay.

      Arnia temperature data - September to December 2018 - broodless in late November


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