Honey bees, Apis mellifera , have for millennia been managed and exploited by humans and introduced into most suitable regions worldwide. However, given the lack of records for many introduction events, treating A. mellifera populations as native would predictably bias genetic studies regarding origin and evolution. Here, we used the Dongbei bee, a well-documented population, introduced beyond the natural distribution range approximately 100 years ago, to elucidate the effects of local domestication on animal population genetic analyses. Strong domestication pressure was detected in this population, and the genetic divergence between Dongbei bee and its ancestral subspecies was found to have occurred at the lineage level. Results of phylogenetic and time divergence analyses could consequently be misinterpreted. Proposing new subspecies or lineages and performing analyses of origin should thus strive to eliminate anthropogenic effects. We highlight the need for definitions of landrace and breed in honey bee sciences and make preliminary suggestions.

Cold tolerance is a key physiological determinant of colony overwintering survival and productivity in honey bees, yet quantitative phenotyping at the individual level remains a major challenge. Here, we developed a novel, non-invasive, multi-cubicle thermal testing platform that integrates the classical chill-coma recovery time (CCRT) and critical thermal minimum (CTmin) frameworks and introduces knockdown time—the interval from spontaneous locomotion to complete immobility under controlled cold exposure—as a quantitative index of individual cold tolerance. We evaluated this system by assaying 323 workers from two western honey bee (Apis mellifera) populations used in Chinese apiculture: the cold-adapted Dongbei bee and the cold-susceptible Apis mellifera ligustica, across two ages (10-day-old nurses and 20-day-old foragers) and two temperatures (6 and 10 °C). Three-way ANOVA revealed significant effects of population, age, and temperature, as well as their interactions: Dongbei bee workers exhibited ~1.4- to 1.9-fold longer knockdown times than A. m. ligustica in all age × temperature combinations, and foragers generally outperformed nurses in both populations, reflecting age- and task-related physiological adaptation. This work establishes a standardized, high-throughput platform for individual-level cold tolerance phenotyping, offering a promising tool for cold-tolerant honey bee breeding and a quantitative foundation for future mechanistic studies of thermal adaptation.