Episode Details

In this BTP Short, Dr. Dewey Caron shares another of his "audio postcards," this time exploring the critical role of fat bees—also known as diutinus bees—in helping colonies survive winter. Dewey explains how these long-lived worker bees differ from their summer sisters, with enlarged fat bodies, higher protein reserves, and lower juvenile hormone levels, all tied to the key blood protein vitellogenin.

Drawing on published research papers, Dewey highlights how environmental cues such as declining pollen, temperature, and daylight trigger the production of winter bees, and how clustering helps colonies thermoregulate through the cold months. He emphasizes that strong, heavy colonies going into winter are far more likely to survive than weak or light ones.

For beekeepers, Dewey stresses the importance of continuous Varroa control throughout the season, fall feeding to ensure sufficient carbohydrate and protein stores, and combining weaker units when necessary. He also discusses drone eviction, stock influences, and climate change modeling that suggests warmer falls may disrupt the balance of winter bee production and survival.

This episode provides science-based insights and practical recommendations to help beekeepers communicate with their colonies—ensuring not only fat bees, but fat, well-prepared colonies for overwintering success.

Websites and Links mention in the episode:

• Dewey's Book, Honey Bee Biology and Beekeeping, 3rd Edition: https://amzn.to/3KezyCs
• Döke, Mehmet A. M. Frazier, and C. Grozinger, 2015 "Overwintering honey bees: biology and management," Current Opinion in Insect Science.
• Mehmet Ali Döke, Christina M. Grozinger. 2017. Pheromonal control of overwintering physiology and success in honey bees (Apis mellifera, L.)
• Döke, Mehmet Ali, CM McGrady, M. Otieno, CM Grozinger, M Frazier. 2019. Colony size, rather than geographic origin of stocks, predicts overwintering success in honey bees (Hymenoptera: Apidae) in the Northeastern United States. J. Econ. Entomology 112 (2), 525-533, DOI: 10.1093/jee/toy377
• Stephanie Feliciano-Cardona, †Mehmet Ali Döke, Janpierre Ale man,Jose Luis Agosto-Rivera. Christina M. Grozinger and Tugrul Giray 2020. Honey Bees in the Tropics Show Winter Bee-Like Longevity in Response to Seasonal Dearth and Brood Reduction. Front. Ecol. Evol., 8. https://doi.org/10.3389/fevo.2020.571094
• Somerville, Doug (2005) Fat Bees Skinny Bees, A manual on honey bee nutrition for beekeepers., Australia. Available on the Web at https://www.agrifutures.com.au/wp-content/uploads/publications/05-054.pdf https://rirdc.infoservices.com.au/downloads/05-054
• Kirti Rajagopalan, Gloria DeGrandi-Hoffman, Matthew Pruett, Vincent P. Jones, Vanessa Corby-Harris, Julien Pireaud, Robert Curry, Brandon Hopkins & Tobin D. Northfield. 2024. Warmer autumns and winters could reduce honey bee overwint