Comparing Southern vs. Northern Queens
Hive Size in the Fall Predict Overwintering Success
Döke, Mehmet Ali, Carley M. McGrady, Mark Otieno, Christina M. Grozinger, and Maryann Frazier. 2018. Colony Size, Rather Than Geographic Origin of Stocks, Predicts Overwintering Success in Honey Bees (Hymenoptera: Apidae) in the Northeastern United States. Journal of Economic Entomology. Accessed January 29, 2019. https://doi.org/10.1093/jee/toy377.
A research team from Penn State University compared the performance of queens bred in southern vs. northern regions at three apiaries in a northern climate (central PA). They measured colony weight, population size and overwintering success. They found that queen origin did not affect colony weight, population, or overwintering success. But heavier and more populous colonies were more likely to survive the winter. And they found that colony weight and population (and overwintering success) differed by apiary location - suggesting that local resources and hive size are critical for overwintering survival. You can read the full article here.
Why did they conduct this research?
Past research suggests that locally adapted stocks survive longer than non-local stocks. A large European study [which you can read about here and here] found that locally adapted stocks survive better than non-local stocks in their home range. In a US study [found here], packages that were re-queened with stock from northern queen breeders had higher overwintering success in a northern climate, compared to colonies left with the original “package” queen. However, it is unclear whether the difference in overwintering success was due to differences in queen quality, the benefits of re-queening, OR the benefits of locally adapted stock. The current study further tested the benefits of locally adapted honey bee lines.
What did they do?
In spring 2013, the researchers established 60 colonies at three locations in central PA, headed by queens from two northern breeders (both from Vermont) and two southern breeders (Texas and Florida). They managed the colonies using standard beekeeping practices, including regular mite treatments. Every month, they monitored colony weight and population size. The following spring (April 2014), researchers recorded overwintering survival. The researchers also analyzed genetic differences between stocks.
What did they find?
The researchers found small but significant genetic differences between the stocks from different regions. Surprisingly, though, the hives headed by northern queens did not grow larger or store more honey than the hives headed by southern queens. However, hives with more bees and honey in the fall were more likely to survive the winter. Apiary location, not genetic stock, was most related to hive size, honey stores, and overwintering success. For example, one apiary (mostly surrounded by farmland) had the largest hives and a survival rate of nearly 80%. Another, in contrast, was surrounded mostly by woods and had a survival rate of only around 50%.
The take away:
We know from previous research that carefully-selected northern queens outperform commercially-produced package queens from the south. This study suggests that, when comparing carefully-selected queens from different regions, location may have a bigger impact than genetic stock. It reminds us that larger hives with more honey stores are more likely to survive the winter, and therefore underscores the importance of local resources on overwintering success. More research is needed to understand the complicated relationship between location and genetics.
Additional citations:
Büchler, Ralph, Cecilia Costa, Fani Hatjina, Sreten Andonov, Marina D. Meixner, Yves Le Conte, Aleksandar Uzunov, et al. 2014. The Influence of Genetic Origin and Its Interaction with Environmental Effects on the Survival of Apis Mellifera L. Colonies in Europe. Journal of Apicultural Research 53 (2): 205–14. https://doi.org/10.3896/IBRA.1.53.2.03.
Hatjina, Fani, Cecilia Costa, Ralph Büchler, Aleksandar Uzunov, Maja Drazic, Janja Filipi, Leonidas Charistos, et al. 2014. Population Dynamics of European Honey Bee Genotypes under Different Environmental Conditions. Journal of Apicultural Research 53 (2): 233–47. https://doi.org/10.3896/IBRA.1.53.2.05.
MacGregor-Forbes, E. 2014. Sustainable Agriculture Research and Education (SARE) Outreach, USDA – National Institute of Food and Agriculture (NIFA) Annual Project (FNE12-756) Report: A Comparison of Strength and Survivability of Honeybee Colonies Started with Conventional versus Northern Requeened Packages. https://projects.sare.org/sare_project/fne12-756/.
