Beekeeping Basics
Fat Bees and Colony Survival
One of the things I love about beekeeping is how much there still is to learn and discover. Any one of us could be the one to uncover clues to enhance the survival of our beloved honey bees. A great example of this is Dr. Sammy Ramsey, whose Ph.D. research paper in 2018 revolutionized our understanding of the relationship between Varroa destructor and Apis mellifera. He discovered that varroa feeds on the fat body of the adult honey bee rather than on the hemolymph, as had been previously thought. This made the modern body of research on bees’ fat bodies and their functions more important than ever.
Understanding of the fat body is important to our understanding of the winter survival of honey bees. The main purpose of the fat body is storage of nutrients and energy. The fat body is also involved in hormone regulation, which in turn is implicated in the longevity of the honey bee as well as her maturation through the tasks in her colony. “Fat body has a variety of functions including energy storage and release, biosynthesis and catabolism, regulation of nutrient perception, integration of metabolic signals, endocrine regulation, immunity and detoxification, magnetic field perception, improved cold resistance, and protection of organs in the body cavity.”2
To put all of that into plain English, the fat body is essentially the liver of the honey bee. Its biggest job is to store energy for the future use of the bee. It also stores nutrients — things like vitamins, polyphenols, and cholesterols — which are used not only for the bee herself, but are also incorporated into royal jelly (fed to the queen), and worker jelly.
A good example of this is 24-methylenecholesterol, which comes from pollen. This particular nutrient is critical for the development and metamorphosis of larvae. Without it, as larvae move from one instar to the next (grow through stages of development), they cannot shed their cuticles (skins), and, being imprisoned in a too-small skin, they die. In winter, when no pollen is coming in, nurse bees tap into the reserves of 24-methylenecholesterol in their fat bodies so that they can incorporate it into the jelly being fed to larval bees that start to be grown after the winter solstice …
