Essential oils and honey bee health
The role that essential oils play in the life of a honey bee colony is complex, fascinating, and not well understood. Beekeepers are just beginning to grasp the potential that these oils may have, and recently a host of scientific papers have delved into various aspects of their chemistry.
According to one paper, “essential oil” is a general term for “liquid, highly volatile plant compounds, characterized by an intensive, characteristic odor” (Imdorf et al. 1999). The essential oils that most people are familiar with are the ones used in food, cosmetics, personal care and cleaning products. These include the oils of lavender, peppermint, pine, clove, spearmint, and citrus. Each oil comprises dozens—sometimes hundreds—of plant chemicals, and it turns out that many of these play an important role in bee health.
The use of essential oils as a feeding supplement first became popular with the manufacture of a commercial mix of spearmint and lemongrass oils called Honey-B-Healthy. The oils are kept in solution with water by the use of an emulsifier so that the product mixes easily with sugar syrup. My personal opinion is that Honey-B-Healthy was a stroke of genius. There is much anecdotal evidence to suggest that the use of Honey-B-Healthy increases overall colony health, and helps bees deal with stress, pathogens, and parasites.
In many ways Honey-B-Healthy seems to act like a vitamin pill for bees—all the phytochemicals in the two oils appear to make up for things that are lacking in the bee’s diet. This is especially important where a naturally varied diet is missing, as is the case on much of our farmland.
After writing a research paper on essential oils and Varroa control, I began experimenting on my own with oils such as tea tree, patchouli, anise, rosemary, and orange. My populations expanded quickly and my bees never seemed healthier. Besides being used as “vitamin pills,” essential oils in various concentrations may be used for many purposes, such as:
- the control of parasitic mites, both tracheal and Varroa
- an aid in the control of Nosema
- an aid in queen introduction
- a mold inhibitor in sugar syrup
- a lure in swarm traps
- a feeding stimulant
For the beginning beekeeper, I would suggest using Honey-B-Healthy in both your spring and fall syrups. Although it is expensive, it seems to increase both the size and health of most colonies. And just for the record, I have no financial interest in Honey-B-Healthy, although I wish I did!