16 August 2013

Combining colonies

On last inspection I realised that one of my colonies wasn't going anywhere useful. This is the one that had a drone laying queen, and had made both what appeared to be a queen cell and an elongated 'drone queen' cell. I couldn't see any eggs or larvae, so there was no active queen and, fortunately, no laying workers either. A test frame from another colony had shown they were eager to produce a new queen - but it's getting a bit late in the late in the year, and it would be mid-September before the colony had its' own foragers.

The brood box was also top-heavy with drones which were clambering over each other on all surfaces, so much so that I suspected that this hive was attracting all local drones that had been evicted from their home colonies. (I've read that this can happen, but have never before seen evidence for myself.)

There were three things I could do:
  • Let them raise a new queen, hope she would be well mated, and hope the colony numbers would build up sufficiently for them to successfully overwinter.
  • Combine them with an adjacent colony.
  • Shake them onto the ground, and let them work out what to do.
I decided on option #2, to combine them with their sister colony which was right next door. I know I should have done it a few weeks ago when I first noted the drone layer, but hope springs eternal, and all that.

Although the thought is quite daunting, combining colonies is quite easy - but there may need to be some preparation which can take several days.

Moving closer
When two colonies are combined they first need to be quite close together, otherwise some foragers will be lost.

The 'three foot or three miles' rule is a truism. I've tested it by moving a hive further than three feet within the small apiary - the bees landed almost anywhere but their hive's new position. This is because they navigate to their colony's entrance with almost pin-point accuracy, and this precise homing instinct doesn't allow much leeway. If the entrance to their home has been moved more than three feet sideways, or more than the depth of the brood box forwards or backwards, returning bees will land on the original spot, cling to a branch, or gather in a disorientated heap on the ground until the cold takes them.

If, however, the move within an apiary is less than three feet to one side, or less than the depth of the brood box forwards or backwards, then the first returning foragers will work their way towards the hive entrance and will fan Nasanov pheromones to tell all the others where they should go.

On this occasion I didn't need to move the hives as the entrances were already within 3 feet of each other, so that one one less thing to do.

Preventing a brawl
One of the colonies needs to be queenless. This may mean searching for, and destroying, the queen that is no longer needed or, if the colonies are being combined to improve a harvest, she could go into a nuc along with frames of brood and a good shake or two of nurse bees and so found a new colony.

The easiest, and least risky, way to prevent the two colonies fighting and killing each other is to separate the two brood boxes with newspaper, preferably a single sheet of a broadsheet rather than two sheets of a tabloid. All I needed to do was decide which was to be the lower box of the combined colony.

Weakest above the newspaper
The usual choice is to put the weakest or smallest colony furthest from the entrance and  above the larger, stronger, queenright one.
  • The two colonies are separated form each other by a layer of newspaper.
  • The lower colony will go about their usual business until the evening comes and all the foragers are inside.
  • The uppermost colony will need to chew through the newspaper to find their way to the hive entrance.
  • A small colony will take longer to chew an escape route than a large colony.
  • A large colony in the upper box can chew through a sheet of newspaper within a few hours, move quickly downwards and easily overwhelm a smaller colony in the lower box.
  • As soon as the newspaper is punctured the colony scents will start to mingle.
  • Some beekeepers like to make two or three tiny slits in the paper, using the tip of the hive tool.
  • The pheromones from the lower box will move upwards with rising warm air. 
  • Once the scent in the two boxes is the same it is unlikely that the bees will fight and kill each other.
  • If there are limited stores, the uppermost colony will need some syrup because they will be unable to forage. This can be critical in Spring and Autumn, when days are shorter.
  • If it's suspected that there is a queen in the upper colony the queen excluder can be left in place - with the added advantage that it will hold the newspaper in place.
So, that's what I did. I added the newspaper and queen excluder above the existing super, having decided it might as well stay there so the returning bees nectar would have somewhere to go, and popped the second brood box on top, Topped it with the crown board and roof and then removed all traces of that hive, including moving its' hive stand well away. (The above picture shows the combined colonies.)

The next day

I took a quick look the next day and saw a little pile of well-chewed newspaper at the entrance.

This told me that the two colonies would have the same scent, and could be working as one, so I took off the top box and checked. Not always a good idea, but I was feeling confident.

The bees had chewed through each corner of the paper. Some drones had committed suicide by getting trapped in the queen excluder, but it didn't matter too much as their days are numbered - and there were still plenty left alive.

I could see no sign of a queen in the upper box, no corpse on the queen excluder and no sign of one on any of the frames which were now almost empty of bees - except for drones and one or two workers. I carefully checked each frame again, to be absolutely sure there were no eggs. Then I did something that isn't exactly recommended, and shook and brushed every single drone from the frames, scored the wax cappings of the arcs of sealed stores, and replaced this brood box above a feeder board - that's a crown board with a central hole. I had felt a bit mean leaving so many drones above a queen excluder, so thought they might appreciate a means of escape. My reasoning behind scoring the sealed stores was that the workers would move this honey down into either the lower box or the super. I'll see if it's worked when I next inspect.

The drones were a bit disorientated for a while and sat in miserable clumps on the ground, almost as if they were working out what to do next. Within half an hour they'd all gone, there were no piles of corpses in front of any of the small apiary's hives, so I could safely assume the guard bees of one or all of the other hives had let them them in.  


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