>I should point you to my comments about the stain also detecting 'soon to be non viable sperm'... I have no idea how a queen deals with this but I do wonder.  I have had the same experience with queens showing up in the spring as drone layers and wonder if this is about original sperm viability or cooler temperatures

Based on decades worth of observation and study: 

1) the process of supersedure is not understood. We don't know if the hive bees replace the queen, or she sacrifices herself. We don't know if the bees' evaluate the queen based on her egg output or by pheromones. Fertility and attractiveness are not directly linked any more in bees than they are in people.

2) we don't know if the queen "decides" to fertilize eggs or if it's a reflex. I don't think she could evaluate the quality of the sperm. Rather, she releases a quantity of semen which has a multitude of sperms, of which a dozen or more may enter the egg. No doubt this is a failsafe measure against poor quality sperm. Competition for access to the egg is a selective process, just as is drone flight.

3) many queens that appear *to us* to be fine, get superseded and sometimes actual drone layers are not replaced in a timely manner, which one expect bees to do. The reason for this *may* have to do with queen attractiveness. One that produces the "right stuff" may be able to retain her throne, where one that doesn't will be replaced. Again, we don't know which decides: the queen, or some squadron of queen monitors.

4) sperm viability may be the tip of the iceberg. If a newly mated queen shows 50% viability, this means she has only half as much sperm as normal available. Depending what is causing the sperm to die, this number may hold or increase. In any case, I doubt she "knows" she is laden with dud sperms. And what is causing this? Nosema, pesticides, temperature change, global warming?

By the way, while 50% inviable sperm will not cause queen failure outright, it could mean that the other sperm is also damaged, but still alive. It would definitely mean a reduction in the number of high quality sperms, and an increased likelihood that the egg will be fertilized by a poor quality genome.

That is, one with internal flaws such as mutations, mitochondrial damage, or other flaws. The drone does not contribute mtDNA to the egg but it does have cellular mitochondria, which are required for energy production. Any mutations in drone DNA are expected to cause that particular haploid drone to die and not pass on the flaw, but damaged genes that do not affect drone functioning could be passed on by a specific drone, especially if he is one of the few still able to get to egg. 

Furthermore, there are specific substances in the semen that may be required to produce a quality queen, if the sperm is 50% inviable, these aspects could be affected as well. 

I would submit that despite all that has been said, commercial queen rearing cannot produce the best possible queens. In nature, except in emergencies, queens are raised from selected eggs. Zero day larvae (eggs) produce better queens that 1, 2 or 3 day larvae. The eggs may be from specific lines as well. 

Whereas, queen breeders typically use day old or older larvae, all pulled from combs of larvae that were destined to be rank and file workers. Nobody has proven for certain that there is a difference between these types of eggs, but in other species there are specific queen eggs. 

Certainly the practice of raising 45-60 or more cells per cell builder, twice a week, could lead to inadequate care, especially a busy season is well underway. How many producers ditch queen cells that are slightly smaller than their ideal, on the assumption that they are "good enough." I was taught that if you aren't throwing cells away, you need to double your output so you can properly cull subpar cells.

PLB

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