Quality and performance of imported and domestic queens

The quality of a honey bee queen and her mating plays a pivotal role in determining the success and productivity of the colony. The goal of this project was to examine the variability among imported and domestic stocks in measures of initial queen quality, relate these measurements to colony productivity, and provide data to support management decisions.

We purchased queens from British Columbia (BC, n=43), New Zealand (NZ, n=42), and Hawaii (HI, n=43), analysed a subsample for morphometric traits, sperm count and viability, and introduced the remainder to colonies at three sites across Alberta, Canada, where they were evaluated across two production seasons. We measured colony-level parameters including the “patchiness” of the brood pattern, hygienic behaviour, disease-tolerance, honey production, adult bee and sealed brood populations, as well as cluster size and colony weight
before and after winter.

The queens received were well-mated (mean 5.9 million ± 0.22 million sperm, range 3.1-10.4 million) stored in the spermathecae of an initial subsample of queens. There were, however, differences among sources for both queen weight and sperm count (NZ 5.3 ± 0.37 million, BC 6.48 ± 0.44 million, HI 5.93 ± 0.27 million). Sperm viability was also high across the stocks (mean = 85.71 ± 1.03%, min = 69.13%, max = 98.17%; NZ = 89.22± 1.80%, HI = 83.30 ± 1.58%, BC = 84.54 ± 1.66%). We also measured the sperm count of surviving queens sampled at the end of the experiment (NZ 4.0 million, n=10; BC 5.4 million, n=7; Hi 3.4 million, n=9).

We found significant differences among stocks. NZ queen-led colonies had less solid brood patterns and smaller brood and adult bee populations, despite the queens having initially good viability and sperm count; this was likely associated with the higher incidence of chalkbrood observed in these colonies, especially in 2018. We will discuss these results and other performance measures that varied among the stocks and sites. The majority of the queens we tested from commercial stocks did not survive through two production seasons, whether through lack of acceptance, supersedure or death.