Re: Curious on Commerical Queen Rearing Yard Rotation
Velbert, When I ready your 20% my first reaction was that is an exaggeration. So I went to the only source of actual numbers I have for now. or at least know where it is.
The following comes from a per on comparison of Instrumentally Inseminated queens to Naturally Mated queens. Arguably it applies due to the following statement.
"Most studies report similar rates among IIQ's (Instrumentally Inseminated Queens) and NMQ"s (Naturally Mated Queens) So the percentages will reasonably apply regardless if they are reporting rates for II OR NM.
1. 1480 total queens mated 1972,73 25.2% and 16.5% failure respectively average 21% This does clearly show that bad years can be very bad as well. A 25% plus failure rate means you have to graft nearly twice as many queens as you want to produce. I will show that in a bit. OUCH!
2. From 1972 to 1983 3440 queens mated 10% failure. a longer time span give a better average loss rate but conceals yearly highs and lows.
3. In 1989 a study reported 15% average failure for a 5 year period.
Related factor. one study showed a 5% failure in queens mated 10 days after emergence. but a 20% failure of queens mated at 13 days after emergence. this alone could account in drastic differences in failure rates.
I included that last line just to show that other factors need to be considered. but overall if your operation is running 20% losses it is what it is. I am just looking to see if such high rates are common.
In the 3 reports above there are 18 years total with an average combined failure rate of 12.59%
Although this protracted average does not support 20% losses. clearly the individual year numbers say that even your 20% claim could be low. Don't you just love numbers? They can pretty much just flat lie to you and you can't argue with them.
What this does tell me is that if you are having higher than 15% losses consistently your time may be better spent not chasing around empty nucs and re queening. but taking a long hard look at how you are getting your queens mated. There very well may be just a detail here or their that can make a big difference. Like trying to make sure your queens are mated at as close to 10 days after emergence as possible. In reading the entire paper temperature and room the queen is kept at after mating also makes a big difference. So High failure rates may better be addressed by looking at the condition of the nuc rather than the queen. I don't consider the above includes losses to queens not returning during open mating. So 20% losses up to actual mating and returning does seem to be very realistic. 20% unsatisfactory layers is also likely but may be preventable.
That is a total of 36% losses, at 50% losses you would have to graft 2 to 1 the number of queens you want to end up with. Clearly there is a lot of room to improve breeding methods.
Significant Minority vs Insignificant Majority, 20% of causes produce 80% of the effects.