How to Encourage Honey Bee Colonies to Construct a Propolis Envelope

When colonies of A. mellifera nest in tree cavities, they line the nest interior with a propolis envelope, which serves many purposes, including waterproofing and preventing fungal decay of the hive walls. Our research shows that honey bees exploit the antimicrobial properties of resins to supplement and stabilize individual immune function, fight off some pathogens and parasites, and promote the proliferation of some microbiome species. In the U.S., colonies derived from A. m. ligustica and carnica that are hived in standard beekeeping equipment made of smooth wood do not construct a propolis envelope. For our research trials, we experimented with different ways to apply or encourage colonies to construct a propolis envelope. We describe the pros and cons of these methods including our latest approach, which is to provide colonies with boxes that are internally rough-cut with grooves 5-7mm wide and deep. In these boxes, the propolis does not interfere with the natural bee space or impede frame movement. The results of large-scale field trials using these boxes will be discussed in a separate talk by Dr. M. Simone-Finstrom. We encourage all beekeepers to encourage bees to deposit propolis within hive bodies to promote honey bee health.