Mike Simone-Finstrom watching propolis foragers.
I talked a little about propolis, human health, how bees collect it here, but now I want to talk about propolis and bee health. If the bees can’t eat propolis, then why would they collect it? It is costly to bring back to the hive since it takes time and energy away from bees that could be foraging for nectar or pollen, so it must have some benefits. And it does! Mike Simone-Finstrom did his PhD work on looking at how propolis affects bee health.
Inside view of a bee tree lined with a propolis envelope.
Bees living in a tree cavity coat the tree walls with what Tom Seeley dubbed a “propolis envelope.” The walls in a managed Langstroth hive are smooth, so bees really only put it in cracks like where the frame edges meet the box and between the boxes. Mike decided to paint the inside of nucleus colonies (5 frame colonies) with a propolis tincture to see if it had any effect on the bee immune system. He found that the bees in the propolis rich environment had a less active immune system, meaning that the bees could invest less in costly immune proteins because propolis acted as a microbial barrier. So, propolis does help the bees.
Mike painting the inside of a nucleus colony with propolis.
If you are interested in getting your bees to make their own propolis envelop in your smooth-walled hive, then rough up those smooth sides. Mike used a sander with the rough wire attachment to mechanically rough up the inside hive boxes. It isn’t exactly easy, but it is do-able. Let me know if you think up a better way to make the inside of a smooth wooden box rougher. Maybe if the bees are busy putting the propolis on the sides of the roughed-up box, then they will be less likely to but it on the frame and box edges.
Very interesting.
One idea to promote the propolis envelope is to build your own equipment using rough cut lumber, smoothing only the outside. Of course you could use cedar and leave the outside rough too.
Woodworkers sometimes use a toothing plane to prep surfaces for veneering or for rough surfacing of difficult grain. This would cut tiny grooves in the surface of the wood that might be ideal for propolizing (is that a word?).
Great ideas! Thanks, Steve!
Katie, will you clarify your comment please? Everyone tells me, and I see it too, that the bees always make the envelope, even in a smooth box. Yet, you wrote
“If you are interested in getting your bees to make their own propolis envelop in your smooth-walled hive, then rough up those smooth sides.”
Are you suggesting that rough sides yields more propolis and more propolis is good for the bees?
We have much better success with bees both collecting propolis and making a propolis envelope in hives with rough interiors. The bees do put a bit here and there in the smooth-walled hives, but not nearly like they do in rough-walled hives. I do not know how much propolis is good for the bees – were the threshold is – but I would guess that more is better in this case and having the propolis cover a larger surface area would be better. Some types and strains of bees are more likely to collect propolis than others, so if your bees already put it all over in the hive then maybe you have one of the high-collecting types.
Katie