March 2025
March 2025 - Alan Riach
Swarm preparation – both bees and beekeepers.
Although early to be worrying about swarming, if we have a mild Spring the bees could be thinking about it before April’s newsletter appears, so make your plans now.
The only reliable means of detecting preparations to swarm is the routine inspection of the brood chamber(s) and that needn’t take long.
Please do prevent swarming if at all possible. Not just for the sake of your honey crop but for the safety and consideration of neighbours. Retrieving bees from buildings can be an expensive process.
How often? Every 7 days if the queen is not clipped and at least every 10 days if she is clipped.
Methods: 4 minute check with twin brood chambers (e.g. using the late Ian Craigs 8+8 system), or with box and half system, take off the supers and lay them on top of the upturned roof at the rear of the hive . Tip up the upper brood chamber and glance underneath (temperature more than 10c with no wind chill and calm weather). If swarm preparations are being made, queen cells will be hanging from the lower edges of the upper brood chamber frames. To tip, insert hive tool between chambers at rear and insert a plastic door hold-open wedge. Then pull the top chamber rearwards by 3 cm to provide stability before tipping up far enough to see under. If advanced cells are seen hanging down then a full inspection is needed and likely artificial swarming.
With a single brood chamber, (8 minute check), it is necessary to go through, checking for queen cells on all the frames. If you should see the queen early on, put her in a cage, then if you find queen cells further along the hive and have to take artificial swarming action, you already have the queen.
Routine inspection timing.
Unless the bees are severely crowded no swarm will go before sealed queen cells are present. (Over super in spring flows to prevent overcrowding). If you saw no charged queen cells (i.e. cells containing royal jelly and an egg), then it will be 8 days before a queen cell is laid-up and sealed, thus 7 day inspection. If the queen is clipped, the inspection time interval could be increased to 10 days. The bees could swarm at day 8 but the queen will be unable to follow and they will return to the hive. Their next chance to swarm would then be day 16 when the first virgin emerges.
Bees whose queen cells have been destroyed may raise a queen from a larva and get it sealed in five days after an inspection (do not use queen cell destruction in an attempt to stop swarming). The inspection timing would then have to be 4 days. If, however, the queen’s wings are clipped, the swarm could try and go at day 4 but would have to return and the new virgin would emerge at day 11 or 12. Thus the 10-day inspection interval is feasible with clipped queens.
Artificial Swarming.
If charged queen cells are found, you must artificial swarm immediately (at least that day).
There are various methods, but all follow the principle of “separating the entities”. If we consider that a colony is made up of 3 entities – a queen, foragers and brood (with its nurse bees). Separating any two of these entities from the third will prevent swarming. Thus Pagden, Snelgrove and Demaree, separate the brood (and nurse bees) from the queen and foragers. The Nucleus method separates the queen and brood (and nurse bees) from the foragers.
At the EMBA Beginners classes we advocate the Pagden system (a horizontal split method), as it guarantees a good quality queen is produced in the original brood chamber containing the brood and nurses and the artificial swarm remaining on the original site remains as a strong foraging force. See https://scottishbeekeepers.org.uk/bee-basics-videos/ If you only have foundation to put into the artificial swarm then include one more frame of advanced brood in addition to the frame containing the queen and place a queen excluder under the brood box (between the brood box and the floor) in case they object to the rather empty box. Leave it there for about a week until the artificial swarm settles. Place a postcard sized piece of card between the brood box and excluder, sticking out the back of the hive to remind you to remove said excluder.
The Snelgrove and Demaree systems follow the same principal in vertical split format but suffer the inconvenience of having to lift off a heavy brood chamber to remove supers and carry out further inspections of the artificial swarm. The Nucleus method removes the queen and brood (including nurses) to a Nucleus box leaving the foragers on the original site with ONE queen cell. If more than one queen cell is left, you have guaranteed a swarm when the first virgin emerges. It is very easy to miss a scrubby wee queen cell hidden in the corner of a frame. The prime virgin will then depart with a swarm perhaps leaving you with a poor wee queen!
Causes of Swarming
There are several reasons for swarming including loss of queen pheromone (the amount of queen substance given off reduces rapidly with queen age). However, lack of space is also a cause of swarm preparation. Early supering is important for this reason. Extra supers should be added under the existing
ones, especially if they have frames with foundation. This makes the bees pass through (and occupy) the new super on their way up to the top super(s). If a super is fullish of honey that also reduces the space available for bees. In order to maintain space for an expanding colony, “over-super” in Spring.
Allowing the workers to move easily through queen excluders also encourages the bees to move up into the super space in Spring. On National and WBC bottom bees-pace hives, avoid using sheet zinc excluders laid on the top of the brood frame top bars as it forms a barrier to the bees moving up into the supers to relieve crowding. If using sheet excluders, add a 7mm x 22mm peripheral framing plus a 7 x15 cross bar, to keep them clear of the top bars of the brood frames. Although more expensive, framed wire excluders are much better – use ones with the wires on one side of the frame (there are wire excluders with the wire in the middle of the framework which confuses the bees somewhat).
Some of you may have watched the recent SBA webinar on varroa resistant queens, which are beginning to appear in numbers. Whilst we’ve been inventing all sorts of ways of dealing with varroa, the bees have been doing what they’ve done over the past few million years whenever a new pest or disease appears – coming up with a way of dealing with it. There is a new EMBA WhatsApp group who are going to investigate how to recognise whether varroa resistance has developed in their bees. Our Secretary can provide a link. However, keep checking (and treating if necessary) until you are confident of determining that varroa resistance is truly established. Alan Riach
