Introduction

Beekeeping is an important industry in Alberta’s agriculture sector. Alberta is the third largest honey producer in North America and the largest in Canada - 40% of the nation’s honey production is sourced from the over 300,000 colonies managed across the province (ABC 2019). The beekeeping industry contributes approximately $500 million to Alberta’s economy annually in the production of honey, wax and pollen and the provisioning of commercial pollination services (ABC 2019).

There are, however, significant challenges faced by Canadian beekeepers. The rate of overwintering colony loss in 2021-2022 was 49.9% in Alberta - the second greatest in Canada and a provincial high since nationally standardized data collection began in 2007 (CAPA 2022). Poor queen quality is the second-most cited reason for colony failure by Albertan beekeepers, with disease being the first (CAPA 2022). Miticides, best practices, and other methods of disease treatment have been or are being developed, but management of queen quality remains an understudied topic and a difficult task for beekeepers to achieve.

As the colony’s sole reproductive female, the honey bee queen is the single most important individual among the 50,000 bees that occupy an average hive (Winston 1987). Healthy queens lay up to 2000 eggs every day, although a break in brood production occurs in winter, and a queen's ability to efficiently reproduce is essential for colony growth and colony survival (Page & Peng 2001). The queen’s genetics influence attributes of her offspring and her presence regulates her colony environment, largely through her pheromones. Colonies that perceive their queens to be of poor quality become agitated, less efficient in honey production and other hive tasks, and may kill the queen to rear a new one (a process that sets the colony back by 3 weeks and disrupts typical age distributions and division of labour) (Winston 1987). Poor queens can lead to weak colonies that are susceptible to disease and unlikely to successfully overwinter, a great cost to beekeepers.

Our goals in this project are twofold:

a)   Evaluate any effect of queen genetic stock on queen and colony success

As queens age, their fertility and pheromone strength decrease, therefore it is generally recommended that beekeepers replace their colonies’ queens every two years, or when a queen is found to be deceased or in poor health (Gruszka 1998). Practically speaking, this is usually done in spring, when surviving colonies are split or new colonies purchased to prepare for the nectar flow and to compensate for overwintering loss. In Alberta and other northern areas, beekeepers establishing queens in the early season are faced with a trade-off: buy queens from overseas that are mated and ready for hive placement upon shipment; or wait to purchase from local breeders. Locally bred genetic lines are thought to be better adapted to northern climates (Holmes et al. 2023), but these same northern climates mean that local queens cannot be reared or mate until later in spring. Our subject queens were from three separate genetic lines (Hawaii, Quebec, and Alberta), allowing comparison among local queens, queens from a well-established overseas company (Hawaii) and queens from an alternate eastern Canadian company.

b)  Identify potential predictors of queen (and colony) success

It is difficult to evaluate queen quality from external factors prior to hive placement. Some physical characteristics, especially body weight, number of ovarioles, spermatheca size, and number of spermatozoa, have been associated with queen quality, though all the above variables except body weight can only be evaluated post-mortem (Hatjina et al. 2014). For these reasons, beekeepers typically associate larger body size with increased queen quality (Prešern & Smodiš 2019). Additionally, some colony-level tests, such as brood laying pattern, have been linked to queen quality, but the accuracy of such tests as predictors of queen quality have been disputed (Lee et al. 2019). Here, we seek to evaluate an extensive set of queen-specific physical characteristics and behavioural tests as predictors of queen and colony success.