Tag: Bob Binnie

  • Queen excluders: are they needed for successful beekeeping?

    Queen excluders: are they needed for successful beekeeping?

    Answer: it depends. That is always the answer for every beekeeping question, or so it seems. Actually, there is one which is always ‘yes’ – see end of this article. When I had kept bees for only two or three years, I decided to forego queen excluders, to see what happened. This is actually quite worthwhile, even if you only do it on a couple of hives, just to observe what bees do when given space and freedom to roam. My biggest ever colony, which was much taller than me, 6 ft (1.83 m), happens to have been one of the ones without an excluder. Unfortunately, the farmer clipped it with his tractor, and it crashed to the ground. The bees exacted their revenge on the fleeing farmer’s head, and then on me as I put it back together again. Anyway, queen excluders: are they needed for successful beekeeping?

    Honey excluder by proxy

    When I learned about beekeeping, initially from evening classes at my beekeeping association, and later from books, the queen excluder was simply part of the hive. It never occurred to me that you could survive without one. Every picture of a hive showed an excluder sitting above a single brood box. It was as important as the roof, as far as I was aware. Later, I discovered exotic practices, such as ‘double brood’ and even the outrageous idea that a queen excluder is, in fact, a honey excluder. I’m in no doubt that it’s not, by the way. However, it could be a honey-excluder-by-proxy (HEBP) if it led to over crowding in the brood nest, causing the bees to make swarm preparations. Wow, HEBP – it just rolls off the tongue, doesn’t it?

    Stored plastic queen excluders
    Stored plastic queen excluders (Paul Horton)

    The purpose of the queen excluder is to prevent her from moving from one area of the hive to another. It does not always work. I have found that my framed wire excluders can be quite leaky, so now I tend to use those flat plastic ones. They are cheaper and seem to work better. Going back to the BIG QUESTION, I believe that the answer is YES. Queen excluders are indeed needed for successful beekeeping if your beekeeping involves raising queens. I would further argue that every beekeeper with more than ten hives should try to raise some queens, but I digress.

    Essential for raising queens

    If you wish to graft larvae from your prized breeder queen, it helps to know for certain that larvae of the right age will be available and conveniently located on one frame. I trust to luck, and mostly that works, but a vertical queen excluder in the breeder queen’s hive can guarantee success. The queen can be placed on a frame containing empty comb and separated from other combs using a vertical excluder. Then, four days later, the comb will contain larvae of the right age because the queen had nowhere else she could lay. It’s a bit awkward making a groove in the hive walls and cutting the excluder so that it slides into place snugly, but it can be done. Bob Bonnie calls it a ‘timing box’. Top tip: use a dark comb or a plastic frame to make grafting with a Chinese grafting tool easier.

    Bob Bonnie explains the ‘timer box’

    Most people who raise queens like to use a queen-right finisher. Cells that have been started off in a queenless colony are placed in a box above a hive containing a queen, but the boxes are separated by supers and one, or even two, queen excluders. Without excluders, there is a risk that the cells would be destroyed, which would be demoralising and a complete waste of resources. I have messed about in the past with re-queening a colony by putting a sealed queen cell in between super frames, then removing the excluder once the virgin has emerged. The idea is that, to the bees, it’s like a supersedure. Once the new queen is mated they will get rid of the old queen and, hey presto, you re-queened a colony with minimal effort. To be honest, it worked for me 50% of the time, but that was only 1 out of 2. Not really a rigorous test.

    Other excluder uses

    Another good use of an excluder is when doing the Ian Steppler boosting method, in which a small colony is placed above a strong one (both have queens). He uses newspaper too. Without the excluder, one queen would be killed, which would be about as far from a ‘boost’ as you could get. Moreover, the Demaree method, as originally described, could not work without an excluder.

    How about this. If you want to harvest a load of nurse bees – to put into mating nucs, for example – you can use an excluder. If you put a box containing open brood above a strong colony with an excluder between boxes, the nurse bees will move up to look after the brood. Drones and the queen can’t get up there. You can then shake the frames, knowing that the queen is safe, and you have got nurse bees for your mating nucs.

    The main event

    Of course, the main use of queen excluders is to keep her majesty away from honey supers so that you don’t get brood mixed in with honey. Or it could be to keep the combs in the honey supers nice and light (brood makes the wax go dark). Some people are not too keen on extracting honey from combs that have had brood in it. I don’t think it’s a problem because the bees clean out cells and polish them, applying propolis as they go. However, if frames have had amitraz strips or other chemicals near them, they should be kept for brood, I think. I haven’t used amitraz for ages as thymol, oxalic acid and formic acid seem to do the trick. Thymol would surely taint the honey, but these things get applied when honey boxes have been removed.

    For the last 7 years I have used excluders in the way that is normal, at least in the UK. They keep the queen from the supers at all times. I’m thinking of going to a sort of hybrid system this coming season. The idea is that in spring and early summer, as the colony is in rapid expansion mode, I will add boxes as the bees need the space, but minus the excluder. This gives the queen the chance to go where she wants and to create the brood nest that works for her. No artificial crowding into one box. However, as we get past the June solstice, she can be shaken (or placed) down into the bottom box with an excluder overhead. She will be laying fewer eggs from then on, and the swarming season will have (theoretically) passed. Any brood upstairs will emerge, and the cells will be cleaned up and used for the forthcoming honey flow in July.

    In the past, when I didn’t use excluders, the queen moved down as the season progressed anyway. She tended to have her nest mostly in the second box up from the bottom, with honey in the boxes above. The bottom box often had a bit of pollen and little or no brood, plus numerous older bees who wanted to kill me, so I didn’t go down there much. The hybrid idea, in which the queen is confined to a single brood box from July onwards, might mean less swarming and more honey. We shall see.

    The answer is yes

    Finally, the question to which the answer is always yes: “If I don’t monitor varroa mite levels in my colonies, and I don’t live in some remote part of Scotland where mites have yet to arrive, should I treat?” Oh, and following on from that, “should I treat every hive in the apiary at the same time?” Yes!

  • Honey Bee Polyandry: The Secret to Their Success

    Honey Bee Polyandry: The Secret to Their Success

    Honey Bee Polyandry: The Secret to Their Success. Yep, a nice catchy headline, but for most beekeepers the polyandrous nature of honey bees is not much of a secret at all. When a virgin honey bee queen takes her risky mating flight to a drone congregation area she will have sex with many drones (male bees) before returning home. It’s quite possible that she carries the sperm of over 30 drones back to her hive. Over the next few days it migrates to her spermatheca and gets mixed up, but not all sperm will be equally represented.

    Getting my head around genetics

    I recently saw a video on Bob Binnie’s channel in which he interviewed Keith Delaplane, of the University of Georgia, about polyandry.

    Anything to do with genetics tends to make parts of my brain leak out of my ears, but after watching that interview I whipped out my copy of Queen Breeding and Genetics by Eigil Holm, followed by some frantic searching on the interweb. Who knows, maybe this time it will make sense, thought I. I’m gradually getting my little mind around this subject.

    The main problem with writing a blog about beekeeping is that nothing I think of to write about is new; somebody has already been there, done that (probably more competently). The main thrust of what I try to do is to get down to actual practical beekeeping, although I do wander about sometimes. This latest bout of researching honey bee genetics does have some implications for my beekeeping, which I will come to, but for now I going to blast through some basics.

    Chromosomes and all that

    The queen is made from a fertilised egg, just like worker bees, but her diet and the way she was cared for during her development ensured that she was special. Not many fertilised eggs get to become a monarch. At a genetic level her cells contain 32 chromosomes, made up of 16 from her mum and 16 from her dad. When she lays an egg, it only has 16 chromosomes. A process called meiosis randomly mixes up bits of genetic material from her chromosomes (some from mum, some from dad) to make the 16 chromosomes in the egg. This happens in humans too; in females while she is a developing foetus, and in males at puberty.

    So, each egg laid by a queen will be unique, with a different combination of DNA from her parents. As she lays her egg she fertilises it with a tiny amount of sperm from her spermatheca, which has been kept safe since her mating flight. The sperm has 16 chromosomes, so that when the two combine we get back to the 32 chromosomes that make a female bee (worker or queen). Because there is sperm from so many different drones inside the spermatheca (I think the record from natural mating is over 70) the resulting workers tend to be half-sisters. Half sisters have the same mum but different dads. There will also be so called super-sisters, made from the same mum and the same dad.

    Why super-sisters? That’s because every sperm produced by a single drone is identical. In humans, meiosis happens in boys, meaning that each sperm carries a mixture of DNA from his mum and dad, so each sperm is different. This does not happen in honey bees. The drone comes from an unfertilised egg; he only carries DNA from his mother. The 16 chromosomes in his sperm are not mixed up with a bit from each parent, because there is only one parent.

    Advantages of hyper polyandry

    It so happens that this process of creating multiple subfamilies (patrilines) within a colony is extremely beneficial. Some of these groups will have a combination of genes which cause certain behaviours to be expressed more strongly than others, such as gathering honey, feeding larvae, or defending the hive. Research shows that hyper-polyandrous queens head colonies that tend to out perform those headed by queens who have only mated with a few different drones. Everything about the way honey bees mate is geared towards massive mixing up of genes to produce huge diversity, even inside a single colony. This must have been an evolved process that succeeded because it enabled the bees to adapt to environmental changes over time.

    Having great genetic diversity may offer survival advantages to bees through adaptation, and certain genes being ‘activated’ by different conditions, but there are limits. For example, the European honey bees have not evolved with parasitic mites, whereas bees in Asia have a long history of such co-evolution. Our bees that do manage to survive varroa infestation without collapsing are having to call on genes that were advantageous for something else, and just happen to help with managing mites.

    Queen breeding

    Anyhow, what does that mean for little ole me trying to raise queens that make loads of honey, don’t sting me very often, and don’t swarm away at the slightest opportunity? I don’t live in an isolated area, and I don’t practise instrumental insemination (yet), so I have to accept that I have no control over the drones that my virgin queens mate with. Nature has no problem with this, but nature doesn’t always produce great bees for beekeepers.

    Some bee breeders create a closed population of bees which are cut off from other bees. The closed population needs to be large enough to retain diversity, and new blood can be brought in periodically to keep things fresh. All of that is controlled with isolated mating and instrumental insemination, which is way beyond what I can do. Most queen producers are not breeders; they take breeding material from ‘proper’ breeders and open-mate virgin daughters with local drones. It works well, but it is subject to nature’s desire for randomness and diversity.

    Rethinking queen selection

    The main thing that strikes me from all of this, apart from how incredible honey bees are, is that I need to rethink my expectations a little. I fall into the trap of thinking that my greatest colonies must be headed by a great queen. I then try to reproduce those excellent qualities by grafting from that queen. But hang on. The majority of the behaviours within a colony are the result of the multiple subfamilies at work in the hive. Sure, they have the same mother, but it is the particular mix of drone sperm that was matched to that queen’s eggs that has caused the perfect blend of qualities that I’m looking for. How likely is it that the daughter queens of that breeder, open mated, will result in the same traits? I’m guessing it’s all a bit of a lottery.

    I still think it’s worth selecting my best queens for making new queens, and I definitely believe that colonies with good qualities should be given plenty of drone comb. The more good drones that we have in our area, the more likely we are to get well mated queens with, hopefully, the traits that we desire. Equally important, and often overlooked, is the removal of drone comb from horrible colonies, and changing their queens. When selecting queens, I need to look at traits that are specific to that queen, not just the subfamilies, when choosing a breeder. These are some I can think of:

    • lays lots of eggs in a beautiful brood pattern
    • strong pheromones, nice retinue of workers around her
    • well mated, longevity?

    Even these few traits are partly dependant on factors outside of the queen’s genetics. The ability to lay lots of eggs can be held back by the number of workers and the amount of nutrition available. However, under good conditions some queens will be able to lay more eggs than others, and that is down to the queen. The brood pattern is a great thing to look out for in my opinion. I presume that brood breaks in winter or during dearths are not so much about the queen, but her workers. Whether or not a queen gets well mated (lots of sperm from lots of drones) could simply be a matter of luck. However, at least if we select breeder queens that were well mated and live for many years there is a chance that some of that is because of her genes. Maybe she has a bigger spermatheca, or stayed out on mating flights longer until she mated with a lot of drones…I’m speculating.

    All of those good beekeeping traits like gentleness, honey gathering, hygiene and so forth seem to be due to the combination of queen plus drones; a combination unlikely to be consistently repeated using open-mating. It therefore remains my job to be ruthless with badly behaved colonies and weak ones that need endless nursing; they should be removed and a new queen + drone combo given the chance.