Swarms and Splits

Beekeeping Fundamentals 2 introduced swarming as how a colony reproduces, and Beekeeping Fundamentals 5 placed it in the year. This chapter looks closer: what makes a colony more likely to swarm, how to tell swarm preparation from queen replacement, what happens to a swarm afterwards, and how beekeepers use the bees' own queen-raising ability to split a colony. It is based on the Colony reproduction, Factors that trigger swarming and Artificial swarming sections of the Beekeeping article.

Two Ways to Replace a Queen

The article says colonies depend on their queen, the only egg-layer. When her pheromones fail (because she is injured, has run out of sperm, or her scent has faded too far to control the bees), the workers make queen cells by modifying existing worker cells that hold a normal female egg. They then either supersede the queen without swarming or divide the hive into two colonies through swarm-cell production, which leads to swarming.

The other article (Beekeeping Fundamentals 2) described emergency queen cells built out from the comb face rather than hanging from the bottom of a frame. The two articles stress different positions, so a beginner should not rely on position alone; the Beekeeping article gives the count as the main difference (check).

The point of the function is the gap: a count of 3 to 11 is not classified by the article at all, so a real hive may show a number that does not fit either pattern. I ran the code and the output is exactly the five lines listed in the comment.

What Pushes a Colony to Swarm

The article cites George S. Demuth for the main factors that raise the tendency to swarm, noting he attributed some comments to Snelgrove:

The article also says different subspecies swarm differently: in North America, northern black races are thought to swarm less and supersede more, while southern yellow-and-gray types are said to swarm more; Italian bees are described as prolific and inclined to swarm, and Northern European black bees as strongly inclined to supersede. Cross-breeding makes it complicated, and the article does not say how these labels map onto the bees you would actually get (check).

After the Swarm Leaves

The article says the old queen leaves when the first queen cells hatch, with a large number of young "wax-secretor" bees who form the basis of the new hive. Scouts look for hollow trees or rock crevices. Within hours the new colony builds wax comb using honey the young bees filled themselves with before leaving. Only young bees can secrete wax, which is why swarms tend to contain more young bees. Often a number of virgin queens accompany the first (prime) swarm; the old queen is replaced as soon as a daughter queen mates and lays.

Back in the original hive, the article says a beekeeper may capture the swarm and put it into a new hive; otherwise it reverts to a feral state. A small after-swarm has less chance of survival and may threaten the original hive if too few bees remain. If a hive swarms despite the beekeeper's preventive efforts, the article says the beekeeper may give the reduced hive two frames of open brood with eggs, so it recovers faster and has a second chance to raise a queen if mating fails.

Splitting a Colony

The article says that when a colony loses its queen it is "queenless"; the workers notice after around an hour as her pheromones fade. They choose cells with eggs less than three days old and enlarge them into "emergency queen cells", about one inch (2.5 cm) long and peanut-shaped, hanging from the centre or side of the brood combs. The larva is fed differently, getting plenty of royal jelly, and emerges as a queen after metamorphosis and pupation.

Beekeepers use this ability to increase colonies by splitting. They take several brood combs from a healthy hive, leaving the old queen behind. The combs must contain eggs or larvae under three days old and be covered with young nurse bees, which care for the brood and keep it warm. These go into a small nucleus hive with combs of honey and pollen, where the nurse bees, finding themselves queenless, begin building emergency queen cells.

Not Yet Verified, and Sources

• Source. Everything attributed to "the article" comes from the plain-text version of Wikipedia's Beekeeping article (about 42,500 characters). I read the Colony reproduction, Factors that trigger swarming and Artificial swarming sections. I read all three in full; the source's splitting passage simply ends before mating and later steps, so those are not covered. Other sections were not read for this chapter.
• Conflicts. Queen lifespan and the number of queen cells differ between the two articles used in this course; the cell counts are compatible, the lifespans are not fully (check).
• Not in the source. A way to score swarm risk, and a rule for what to do with queen-cell counts between 3 and 11. The function above is only an illustration.
• Code. A short Python script ran the classification and the tally. Its output matches the comment in the code block and the figure printed on the page.

Exercises