Summer indoor queen banking as an alternative to outdoor queen banking practices

Abstract Honey bee queens are the most critical individuals of a complex eusocial society. Queen banking is the storage of queens individually in cages and placed in a colony to be cared for by worker bees. Queen producers bank excess queens as seasonal demand subsides in the summer to provide an on-demand supply to beekeepers. This approach, however, might be threatened by wildfires, decreased forage availability, and climate change. For this study, we compared current summer outdoor queen banking practices in northern California with banking in indoor temperature-controlled storage facilities to investigate the effectiveness of indoor storage as an alternative to outdoor storage in the summer. Treatments were separated into three groups: indoor queen banks, outdoor queen banks, and a set of unbanked control queens provided with three different stocking rates (50, 100, and 198 queens per bank). Queen quality parameters and survival data were assessed using laboratory and field assessment methods. We found no significant difference in queen quality parameters apart from the weight of indoor queens banked at the rate of 100, which were significantly lower than the other banking rates. Queens stored indoors had a significantly higher survival of 78 ± 1% than queens stored outdoors with a survival of 62 ± 3%. Indoor banking performed better in quality and survival as compared to outdoor queen banking. Therefore, queen banking has the potential to mitigate the valuable fall queen supply caused by rising hot summer temperatures. GRAPHICAL ABSTRACT