Genetic variation in honey bee queen reproductive performance: implications for colony growth and sustainability

The reproductive performance of honey bee (Apis mellifera L.) queens is a key determinant of colony health and productivity. However, variation in queen fecundity among different genetic stocks remains poorly understood. In this study, we compared the egg-laying capacity and colony demographics of queens from three different genetic stocks as Russian, feral, and commercially reared stocks over multiple years (2020, 2021, and 2024). Queens of the same age were produced from a single mother colony of each stock and open-mated during the same year as the experiment, with 3 colonies per genetic stock in 2020–2021 and 6 colonies per stock in 2024. Using standardized colony conditions and controlled assessments of queen egg-laying rates, we found that Russian and feral queens exhibited significantly higher fecundity than commercial queens (χ2 = 18.31, df = 2, p < 0.001). In 2024, we further observed that worker populations in Russian and feral colonies increased over time, whereas commercial colonies experienced a decline, suggesting potential differences in colony sustainability. The estimated worker numbers in the beginning in commercial (t(5) = −1.64, p = 0.16), Russian (t(5) = 1.65, p = 0.16) and feral (t(5) = 2.12, p = 0.08) colonies were 14,456 ± 1,245.37, 9,778 ± 1,075.23, and 9,278 ± 981.40, respectively whereas those in the end in these colonies were 12,284 ± 1142.95, 11,295 ± 727.07, and 13,019 ± 941.82, respectively. While no significant differences were detected in pollen storage (F2, 46 = 0.52; p = 0.65) or brood areas (χ2 = 1.65, df = 2, p = 0.44) in earlier years, trends in brood production aligned with egg-laying patterns. Our results highlight the importance of genetic stocks in shaping queen reproductive performance and colony growth. These findings provide insights for breeding programs aimed at improving queen quality and colony resilience, particularly in the face of environmental stressors such as Varroa infestation and resource availability.