Making Splits

Splitting a colony (making a split, artificial increase) means creating a new colony under the beekeeper's control by taking brood, bees and stores from a strong honey bee colony. It is the most common way of increasing colony numbers; at the same time it prevents swarming and opens up opportunities for requeening and varroa control. Its success depends on the right timing and on leaving the new colony enough bees and food.

Why split a bee colony?

• To increase colony numbers: To replace winter losses or expand the apiary.
• To prevent swarming: To satisfy the colony's urge to divide under the beekeeper's control, before a swarm leaves.
• To requeen: To try out a new queen in a small split and use her once she has proved to be good.
• To create a broodless period: When all the brood has emerged in the queenless part, the colony is briefly broodless; this is a favourable window for varroa treatment.
• To keep reserve colonies: Small colonies (nucs, nucleus colonies) are kept on hand to supply queens, brood or bees to hives that become queenless.

When should you split a hive?

Two things determine when to split: the strength of the colony and the presence of drones in the area.

• The colony must be strong: As a general guide, the hive to be split should have at least five or six full frames of brood and a population that covers these frames with plenty of bees. Splitting a weak colony produces two weak colonies.
• Season: Late spring and early summer are the best time. Nectar and pollen are still coming in and drones are plentiful; the new colony has time to develop with a mated queen and prepare for winter.
• Drones are a must: If there is no sealed drone brood in the hives and no flying drones, a split made with a queen cell or a virgin queen may fail; the new queen cannot mate.
• Late splits: A split made in late summer should be given a mated queen; otherwise the colony will not be ready in time for winter.

Splitting methods

1. Making a nucleus colony (nuc)

This is the most common and safest method. A small colony is set up by taking a few frames from the parent colony; the parent colony stays strong without being weakened.

1. Find where the queen is; set aside the frame with the queen or make sure she stays in the hive, so you do not move her by mistake.
2. Put 2–3 frames of brood into the new hive (the nuc box); at least one should be sealed brood about to emerge, and preferably one should have eggs and young larvae.
3. Add frames of honey and pollen at the sides.
4. Move the frames together with the young nurse bees on them, and shake in the bees from one or two more frames as well. Because foragers will return to their old site, the bees remaining in the split must be young bees.
5. Give the new colony a mated queen or a ripe queen cell, or let the colony raise its own queen.
6. Reduce the entrance and feed with thin syrup if necessary.

2. Splitting in half

The strong colony is divided in two: brood, honey and bees are shared roughly equally between two hives. One hive stays on the old site and the other is placed beside it, or the two hives are placed on either side of the old site so that the foragers divide between them. The half left without a queen is given a queen or a queen cell. It gives rapid increase, but if done before the main nectar flow, that year's honey yield falls.

3. Splitting in the same apiary or moving to another apiary?

If the split stays in the same apiary, the foragers return to the old hive and the split is left with only young bees; this is why extra bees are shaken in. Taking the split to another apiary at least 3 km away keeps the foragers in the new hive as well.

How do you give a queen to a new split?

• Mated queen: After the split has been left queenless for a few hours to a day, the queen is introduced in an introduction cage with a candy plug. The hive is not opened for about a week; then check for eggs.
• Queen cell: A ripe cell a day or two from emergence is placed in the upper part of a brood frame, upright with its tip pointing down, close to the warm brood nest. The cell must not be jolted or turned upside down.
• Raising its own queen: The split must contain eggs and very young larvae (less than three days old). The bees build emergency queen cells from these larvae.

Timetable after splitting

Common mistakes when splitting colonies

• A split that is too small: A colony set up with few bees cannot keep the brood warm or defend its entrance, and gets robbed.
• Not leaving enough food: The new colony has very few foragers; honey, pollen and, if necessary, syrup are essential.
• Not adding extra bees in the same apiary: The foragers return to the old hive and the split empties.
• Moving the queen to the wrong side: You need to know where the queen is before splitting, or check for eggs afterwards.
• Splitting late: This produces a weak colony that will not be ready for winter.
• Ignoring varroa: Splitting also divides the mites; a split made from a colony with a high mite load will have problems too.
• Splitting a diseased colony: Brood diseases are carried on frames; splits are made only from healthy colonies.