-Understanding the reproductive potential ("quality") of queens bees can provide valuable insights into factors that influence colony phenotype. We assayed queens from various commercial sources for various measures of potential queen quality, including their physical characters (such as their degree of parasitism), insemination number (stored sperm counts), and effective paternity frequency (number of drone fathers among their offspring). We found significant variation in the physical, insemination, and mating quality of commercially produced queens, and we detected significant correlations within and among these various measures. Overall, the queens were sufficiently inseminated (3.99 ± 1.504 million sperm) and mated with an appropriate number of drones (effective paternity frequency: 16.0 ± 9.48). Importantly, very few of the queens were parasitized by tracheal mites and none were found with either Nosema species. These findings suggest possible mechanisms for assessing the potential fitness of honey bee queens without the need for destructive sampling.honey bee queens / reproductive potential / insemination / parasitism / effective mating frequency

No abstract

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.

In honeybee colonies, reproduction is monopolized by the queen while her daughter workers are facultatively sterile. Caste determination is a consequence of environmental conditions during development, during which female larvae may become either queens or workers depending on their larval diet. This bipotency introduces significant variation in the reproductive potential of queen bees, with queens raised from young worker larvae exhibiting high reproductive potential and queens raised from older worker larvae exhibiting lower reproductive potential. We verify that low-quality queens are indeed produced from older worker larvae, as measured morphometrically (e.g., body size) and by stored sperm counts. We also show, for the first time, that low-quality queens mate with significantly fewer males, which significantly influences the resultant intracolony genetic diversity of the worker force of their future colonies. These results demonstrate a reproductive continuum of honeybee queens and provide insights into the reproductive constraints of social insects.

The most economically important parasites of honey bee, Apis mellifera L. (Hymenoptera: Apidae), colonies are the parasitic mites Varroa destructor Anderson & Trueman and Acarapis woodi (Rennie). Research has shown that mite-tolerant stocks are effective means to reduce mite infestations within colonies, but it is unclear whether the stocks available commercially are viable means of mite control because they are likely to be genetic hybrids. We compared colonies of a standard commercial stock ("Italian") with those of a commercially purchased mite-tolerant stock ("Russian") for their levels of varroa and "tracheal" mites (A. woodi) over the course of 2 yr in three different geographic locations. We were unable to detect significant infestations of tracheal mites; thus, we were unable to adequately compare the stocks for their tolerance. In contrast, we found significant differences in the levels of varroa mites within and among colonies located across the three different study sites for both years. By the end of the first year, we found statistically significant differences between the stocks in varroa mite intensity (mites per adult bee), such that Russian-hybrid colonies tended to have a significantly lower proportion ofparasitized adult bees than Italian colonies. In the second year, we found statistically significant differences between the stocks in varroa mite load (daily mite drop), such that Russian-hybrid colonies tended to have lower total numbers of mites than Italian colonies. These findings suggest that beekeepers may benefit by incorporating commercially purchased mite-tolerant stocks into their existing integrated pest management programs.