1 Regular check for queen cells/swarm control/clipped queens
2 Check for brood disease, esp. EFB
3 Add supers as required
4 Clear/extract/replace supers after oilseed rape flow
5 Monitor Varroa situation
We are having a wonderful spring at the moment, and the bees are building up quickly, foraging on cherries, plum and increasingly oilseed rape. In fact even my hive that started with a tiny cluster no bigger than a couple of cupful’s of bees has expanded to occupy more than 2/3 of a national super.
This month, you should be checking your hives at weekly (if you have an unclipped queen) or at 10 day intervals (if she is clipped) to spot the first signs that the bees are preparing to swarm. Remember, it only takes 8 days from the queen laying in a queen-cell to the time it is sealed, and on that day, or the first fine sunny day thereafter, the old queen will usually leave the hive with between a third and a half of the workers. They will cluster for a while (anything from a few hours to one or two days) quite close to the hive whilst scout bees search for a suitable new home, and if not captured by the beekeeper, will leave for an unknown destination. If, however, the queen’s wings have been clipped, then when the swarm emerges, either the queen will drop onto the grass and be lost, in which case the swarm will return and await the first virgin to emerge before they can swarm, or the bees will find the queen and cluster around her very close to the hive. You can see why you need to be vigilant.
If however you find occupied queen cells, you need to make an artificial swarm (see April’s notes) unless you can visit your apiary daily and so pick up any swarms that emerge.
Fields of oilseed rape will have been in flower for 3 weeks or more, and supers should have been added well in advance of them being needed. From the middle of this month, you will hopefully have full supers to extract – so long as the combs are at least 2/3 sealed then it should be ok to clear the bees and remove the super/s. Clearing bees can be achieved using porter escapes or one of the more rapid methods based on the Canadian clearer boards.
Whilst you are inspecting your hives, do carry out a disease check of the brood, especially looking at one or two frames containing larvae after shaking off most of the bees, to check for European foul brood, for at this time of the year it is much easier to spot.
Lastly, don’t forget to keep monitoring the Varroa levels in your hives, and if the counts indicate that the mite population in your hives is reaching a critical level, then you need to do something to lower the population. Making a shook swarm in a fresh broodbox and then treating the displaced bees and brood in the original broodbox with Apiguard will control the mite population. Using mesh floors on all your colonies may keep mite numbers at a reduced level, but you must clean the collecting tray at least weekly if problems with wax moth are to be avoided or perhaps leave the collecting tray out altogether.