The Dance floor.

[Greengage]

I was recently asked do honey bees add propolis to the dance floor to improve vibrations in the hive. I had to admit I never heard of this could it be true.

[Mellifera Crofter]

Yes, they thicken the rims of cells with propolis, and they have a preferred area on a comb near the entrance that they use as a dance floor. See Jürgen Tautz, The Buzz about Bees. He explains that the propolis rim acts like a communication network. Worker bees on other parts of the comb detect the vibration coming from a dancing bee, and can then find the dancer to follow the dance, and the message.
Kitta

[gavin]

I'm going to go out on a limb here and declare scepticism of Tautz' comments in his book. They seem to be just opinion without the presentation of data to justify them (like my comments below ;)). Yes, they often dance on comb near the entrance and potential foragers gather there. Yes, bees do propolise cell rims. But I don't think the two are linked. They may thicken rims with wax to strengthen comb in warm places but I doubt that is to do with acoustics, just engineering. They dance just as easily on sealed brood as they do on open brood. On the woodwork, even on their nest-mates especially on a swarm. Bees attentive to the dancers go right up to them with antennae pointed forward. I think propolis on comb is more to do with its antiseptic effects.

[Calum]

I guess they propolis there, because they dont wipe their feet when they enter the hive, so need to keep that area a bit cleaner....
Maybe they need a door mat. (I have been on the mulled mead)

[gavin]

Ah, but do they?! Can't say I've ever looked carefully but my recollection is seeing propolised rims of unused comb, maybe to help preserve it for later. The cells in the active brood nest seem to have thickenings of wax on the rims, as you can see in the picture in Tautz' book. Maybe it is for strength, maybe it is there because they want to increase the cell depth and its left there for later. Maybe I'm completely wrong (Sober as a judge .. )

[Mellifera Crofter]

Yes, Gavin - I've also seen them happily dancing everywhere, but Tautz did not say they exclusively dance on the dance floor, but that the vibrations from the dance floor help to attract distant bees. I found this paper (http://casas-lab.irbi.univ-tours.fr/Tautz%20et%20al.%202001_JEB.pdf) by Tautz & kie. Does that count as serious research? I noticed though that he used the words 'may' and 'could' in that paper - so, perhaps I was wrong to mention it as fact in my reply to Greengage.

(I'm referring to his paper, but I'm not going to attempt reading it. I'll stay with his book which is aimed at people like me.)

This is the image from the book (but it sounds as though you have it, anyway).

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Kitta

[Greengage]

Thanks for the replies.

[gavin]

Hi Kitta

On the propolis question, I was happy that you represented what Tautz said in his book correctly. It just seems unconvincing to me.

The paper is interesting. They finish with these words:

'Our demonstration of the phase-reversal phenomenon in the vibratory signals in the comb suggests that substratum
vibrations cannot be ruled out as a communication pathway simply because their amplitude appears to be too small. '

A pretty modest claim, as authors of refereed papers make when they know they haven't demonstrated it to everyone's satisfaction (or maybe when directed to by a critical referee).

It may have a role ... but they did say that they had to keep changing the comb when the bees filled the cells with honey!

Thanks for asking the question, GG.

PS There was nothing in the paper on propolis - that just appears in the book.

[Greengage]

So I would be safe in saying that yes it is possible but there is no conclusive proof that they actually do this.

[Adam]

It is quite possible that there are resonances in the comb although with variable amount of 'stuff' in the cells, and vith variable amounts of wax in the construction, I would expect the resonances to be quite damped (in an engineering sense) even on the dance floor. I would be surprised if these resonances were fine-tuned by the addition of propolis.
If bees want to make a noise, then they can - we can hear a queen piping from outside the hive so it's not unreasonable to assume that bees can sense the vibration of a sister - whether it be queen or worker - when required to do so when inside it.