From Michael Bush website
http://www.bushfarms.com/beesqueenrearing.htm
He states that emergency queen cells may be inferior if they are made from cells on old comb:
Emergency queens:
“It has been stated by a number of beekeepers who should know better (including myself) that the bees are in such a hurry to rear a queen that they choose larvae too old for best results. later observation has shown the fallacy of this statement and has convinced me that bees do the very best that can be done under existing circumstances.
“The inferior queens caused by using the emergency method is because the bees cannot tear down the tough cells in the old combs lined with cocoons. The result is that the bees fill the worker cells with bee milk floating the larvae out the opening of the cells, then they build a little queen cell pointing downward. The larvae cannot eat the bee milk back in the bottom of the cells with the result that they are not well fed. However, if the colony is strong in bees, are well fed and have new combs, they can rear the best of queens. And please note– they will never make such a blunder as choosing larvae too old.”–Jay Smith
He also notes the relationship between weather and development time:
Transfer queen cells to mating nucs. On day 14 the cells are at their toughest and in hot weather they may emerge on day 15 so we need them in the mating nucs or the hives to be requeened if you prefer, so the first queen out doesn’t kill the rest.
In hot weather, queens may emerge on day 15! Queens emerge (In hot weather, 15 is more likely. In cold weather, 17 is more likely. Typically, 16 is most likely.
There is some research relating the age of the larva to the productivity of a queen:
http://www.beekeeping.com/articles/us/grafting.htm
This paper tested the queen weight, days until the queen started laying, size of the spermatheca and number of sperm in queens, grafted from 1 or 2 or 3 day old larva.
I, too, was reading the Michael Bush website on queen rearing. The part that caught my eye was about bee density:
“The most important thing about a cell starter is that it’s overflowing with bees. Queenless is helpful too, but if I had to choose between queenless and overflowing with bees, I’d go for the bees. You want a very high density of bees. This can be in a small box or a large hive, it’s the density that is the issue, not the total number. There are many different schemes to end up with queenless crowded bees that want to build cells, but don’t ever expect a good amount of cells from a starter that is anything less than overflowing with bees.”
He then goes on to talk about how he achieves this density:
“The simplest way I know of is to remove a queen from a strong colony the day before and cut it down to minimum space (remove all the empty frames so that you can remove some boxes and, if there are supers that are full remove those). This may even put them in a mood to swarm, but that will make a lot of queen cells.
It sounds to me like he is talking about removing the queen and crowding two strong boxes of bees into one if possible. I’m not suggesting that we really try that at this point in the season but it does give an idea of how thick the bees need to be in the cell builder. Maybe with the number of bees we have we would be better off building very small dense nucs, just a couple frames, like those in the queen castle in Round 1.
Just a thought.
About bee density:
The OSU paper Doolittle method of making the nurse hive was to use very full queenright hive after removing the queen. In other words pull the queen and a couple of frames to support the queen and put those in a new nuc or hive and just use the original hive for the nurse colony. This may sacrifice the original hive in a sense, but may be the best way to have the density of nurse bees necessary.