Perry where are you getting your queens from? and where did they come from last year?
The first issue in queen supersedure in packages and nucs is that it is always a push to get them produced and to the customer early in the season so they have a longer time to build up. It doesn't take very much bad weather, to windy, to cold, rain, or the fact that the queens are being raised in a small matting nuc that doesn't have the population to warm the mating nuc to promote early bee flight. Any of these factors can effect whether a queen is mated well with mutable drones or mated poorly. In the 80's before mites, the queen failure rate could very from one year to the next and these queen were coming out of California, one of the best areas for the raising of queens. Fast forward 30 years , the weather is more unpredictable than ever, a lot of the original proven breeder stock has been lost to bee colony die outs and we are treating and manipulating colonies to control the mites and viruses in the hives.