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Hole sizes for Bee Hive Crown Boards
The reason for the trial (if it can be allowed such a grand title as it is quite a trivial experiment) was to see if there was any particular size that the bees preferred. There was no planned structure to the trial, which simply consisted of a series of crown boards, with a 9 mm rim on one face, with central circular holes. The hole sizes tried were 19 mm, 25 mm, 32 mm, 38 mm, 44 mm, 50 mm, 63 mm, 75 mm, 100 mm, 200 mm, 230 mm, 340 mm.
I think 150 mm was also tried, but I cannot find the item physically nor can I find any reference to it in my (rather scruffy) notes.
Method The experiment had no controls, each board was used as and when required by the management of the bees and took place at different times during the year. The “results” are entirely subjective as no finite system of evaluation had been “thought up”. The boards were used over colonies of various sizes and vigour, but this did not appear to affect the results.
The main thing these boards were used for was to isolate a top chamber or space within the hive that the bees would consider as “outside” their domain. Scraps of comb and sometimes broken frames were placed in this chamber if they contained honey, pollen or brood.
Under no circumstances was it noticed that pollen was removed from comb placed for cleaning. In one case pollen stores were added to (that was a 75 mm hole).
Holes 50 mm in diameter, or smaller, always resulted in any honey being removed and placed lower down in the main chamber.
Holes of 100 mm and upwards often resulted in wild comb being built (but not in every case).
One board with a 32 mm hole was inadvertently left in position from June to the following April with a shallow comb that was originally honey, but had a broken lug, as the only thing in the upper chamber (a 75 mm eke). The frame was well propolised and some brace comb fixed it firmly in place, but the remainder of the volume of the chamber was free from wild comb. The broken frame was still being used for honey storage even though it was on its side.
Brood that was sealed was usually abandoned, but some of it emerged. Brood that was unsealed was always tended if the hole size was greater than 100 mm.
The only conclusion that I hold with any conviction is that holes 50 mm in diameter or less are treated differently to holes larger than 100 mm.
In addition to the above I have experimented with holes of 8 mm in diameter drilled in aluminium plates that cover feed holes or porter escape holes. These were used as a method of uniting a super of bees and honey.