CHESHIRE BEEKEEPERS' ASSOCIATION

Apes curamus et nos curant (We look after bees and they look after us)
Founded 1899
Registered Charity No. 227494
We've been buzzing over 100 years 1899-2016

A Volumetric Approach to Swarm Control

A single National brood chamber with 11 deep frames presents approximately 55,000 cells at 25 per square inch. We are told repeatedly that 55,000 or more is the number of adult bees which must be accommodated at the peak in July. As an adult worker measures �� x �� x ��, each requires 1/8 sq in of standing room i.e. no more than 8 per sq in, or about 1/3 the number of cells per sq in.

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number of adult bees. This height can be achieved by adding 3 supers (6" each), but these make no provision for the adult bees to move around overnight when the foragers are back home. Hence, four is probably a better estimate of the number of supers required by mid-Summer simply to accommodate the adult bees in reasonable comfort, regardless of the amount of nectar/honey to be stored.

Since overcrowding is cited as one of the factors involved in swarming, adding supers simply to provide space for the workers is recommended. This provision requires a greater investment in shallow supers than is necessary for the amount of surplus in a normal season but allows for say 120lbs of surplus in bonanza years when swarming is most likely to occur. On balance it is better to be faced with the need to extract part-filled supers in normal years than to be left with empty supers because a swarm has absconded.

I am not suggesting that the above is sufficient in itself to prevent swarms but it does allow for part of one's anti-swarming measures to be quantified.

To continue, readers will be aware that one of the perennial topics in beekeeping is whether or not the BS National brood box is big enough. As noted above it contains circa 55,000 individual cells. The text books tell us that a young queen lays 2,000 eggs daily while the colony is expanding in Spring. That being so, 42,000 cells are required for each cycle of worker brood, leaving 13,000 cells (the equivalent of 2.6 frames or 24% of the total) for drone brood, pollen and nectar/honey. My experience tells me that a quarter of each frame is amply sufficient overall for drones and pollen, and if space in the brood chamber becomes limiting the bees will put any excess of honey "upstairs" where I preferred it to be to maximise the eventual surplus.

I personally think the National BC is big enough unless one is working with prolific queens bred in warmer climes. My preference was always for locally bred queens derived from strains adapted to the area, and whose thriftiness was an important characteristic for their survival in poor Summers and/or harsh Winters.

The twin parameters a) that the queen lays 2,000 eggs per day and b) that a fully developed colony comprises 60,000 adults, are embedded in beekeeping folklore, but I do not know the basis for them. Can anyone give references to the original studies on which they are based? If they should turn out to be not well founded, not only might this article have to be reconsidered from a fresh perspective, so too might some of our basic assumptions regarding colony dynamics.

Malcolm Brierley

(a brood cycle of 42000 implies an adult population, eventually, of about 84 K which would require at least 8 supers + single brood-box to contain them�just to contain them, nothing else.�Ed.)

© 2015 Cheshire Beekeepers' Association