If 'normal' bees make 4.9 comb and we've just bred them larger and larger to 5.4 comb, would it make sense to try to bred them smaller and smaller even past 4.9? If mites don't like the 4.9 because its too small, why don't we selectively breed to 4.5 or so?
First this is not "breeding". The size of the bees is determined by the size of the cell, not by genetics. The tendancy to prefer to build a particular size cell may be genetic, but I personally don't think so.
The concept of raising bees on smaller cells was tried back in the 1800s, not for the purpose of controling mites, but to get more worker brood per comb. It was not very successful because it stressed the bees, as the enlarged comb does also, but in different ways. The smaller bees were not very productive.
I think 4.8 to 5.0 is the normal size for a bee and therefore provides the least stress.
Hi Michael and Branman,
I have a different perspective on the role of genetics in cell size and resulting bee size.
In my top bar hive experiment it was the small cell bee that drew out the large cell comb. Six weeks later, those same large cell bees that hatched from that large cell comb, were the same bees that drew out the small cell comb in my top bar hive!
Cells are not constructed by a single bee but are the result of much cumulative effort. Yet, a mix of bees raised from different sized cells will consistently build a comb with the appropriate size at a given location. Somehow the individual bee can determine just what kind of cell is needed at a given location and do its small part of that cells construction.
Each bee is capable of building cells that range from those smaller than a worker sized cell to very large honey storage cells. Location and function appear to control the size of the cell and not the size of the cell the bee was raised in.
It appears more genetic than anything else to me.
The natural range for worker brood cell size is 4.6mm to about 5.6mm. 5.2mm appears to be about the median size overall. But size is very dependant upon location. 4.6mm is found at the bottom of the core area of the broodnest. 5.6mm is on the exterior portions of the broodnest. And 5.4mm everywhere in between. Cell sizes taper between these areas.
I, think Michael is quite right in stressing the importance of a natural range of cell sizes. AI Root wrote about the smaller sized cells that were promoted in Britain and Europe. I don't remember now just how small the cells were but if I recall correctly they were 4.6mm or less. It appears that the bees will suffer when restricted to any one cell size whether large or small.