Assessing the mating 'health' of commercial honey bee queens

Honey bee queens mate with multiple males, which increases the total genetic diversity within colonies and has been shown to confer numerous benefits for colony health and productivity. Recent surveys of beekeepers have suggested that 'poor queens' are a top management concern, thus investigating the reproductive quality and mating success of commercially produced honey bee queens is warranted. We purchased 80 commercially produced queens from large queen breeders in California and measured them for their physical size (fresh weigh and thorax width), insemination success (stored sperm counts and sperm viability), and mating number (determined by patriline genotyping of worker offspring). We found that queens had an average of 4.37 +/- 1.446 million stored sperm in their spermathecae with an average viability of 83.7 +/- 13.33%. We also found that the tested queens had mated with a high number of drones (average effective paternity frequency: 17.0 +/- 8.98). Queen "quality" significantly varied among commercial sources for physical characters but not for mating characters. These findings suggest that it may be more effective to improve overall queen reproductive potential by culling lower-quality queens rather than systematically altering current queen production practices.