Has anyone ever seen wasps eating through sunflower stalks?

welcome to GoY
this sounds like they are collecting material to make new nest material. they use the cellulose to make 'paper' for their nests. sunflower stems are tough so the cellulose from the plant cells would make good paper.

Makes sense SBG - they chew the wood off our garden table to do the same thing.

i found a nest with blue in it from my blue fence quite amazing

I have just had an 8 foot sunflower topple over due to being eaten by wasps.2 others are affected so we have banked the soil around them. My husband is a joiner and the wasps usually go for the wood left around in the garden but for some reason they have gone for the sunflowers this year. Must be a good vintage for sunflowers.

must be lol cant you just wrap the stalks up

My childrens sunflowers are currently being eaten by loads of wasps. I am desperate to save them as they are massive - what can I do??

wrap them in tin foil from top to bottem

I have just observed 6-7 wasps at the base of one of my sunflowers. I notice that all 8 of them have been stripped of the outer layer at the base, but they are still standing at the moment - thanks to the helpful tips above, I'll be making a earth mound & wrapping in tinfoil - thanks

your welcome