> Many beekeepers now struggle to keep queens laying for a single year. But it is clearly a problem of "modern times", as my average and outlier useful queen lifespans have gone down as compared to even the late 1980s and early 1990s.

What evidence do you have of this? None, I would guess. On the other hand, Dave Tarpy and all did extensive work on this issue:

> The intent of this study was to determine if commercially produced honey bee queens are of low reproductive potential and may therefore explain their diminished quality perceived by the industry. However, our data shows very little, if any, evidence that this is the case for newly mated queens. These findings corroborate Delaney et al. (2011), who also suggest that commercially produced queens are generally high in their reproductive potential. 

> Our large-scale study indicates that the ongoing issues of poor queens experienced in the industry is unlikely because newly mated, commercially produced queens are systemically of low reproductive potential. Thus, we do not currently have evidence as to why the perception among beekeepers is that overall queen quality has diminished in recent years. Therefore, it is likely that if queen quality is an important factor in honey bee management, then testing the numerous environmental factors that can influence queen productivity after mating should take priority.

> there have been surprisingly few studies that have systematically and thoroughly assessed mating frequency, insemination success, and morphometric characters of queens produced by the commercial queen-production industry in the United States. Camazine et al. (1998) investigated the health of commercially purchased queens in the United States.

Assessing the Mating 'Health' of Commercial Honey Bee Queens
DAVID R. TARPY, JENNIFER J. KELLER, JOEL R. CAREN, AND DEBORAH A. DELANEY
J. Econ. Entomol. 105(1): 20Ð25 (2012)

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