What is this!?

[croft36]

I have never been able to establish what this is?! It is of a woolly texture and I usually find it between sheets of wood or plywood stacked close together in a slightly damp shed. This example is from underside of a wooden trunk which has stood on wooden shed floor fo many years. Any ideas please?

 

[MARK.B.]

Wet Rot

 

[TheTiddles]

Fungus

 

[Alpha-Dave]

Wet Rot

I thought Dry Rot; my understanding was that with wet rot, the wood just becomes softer and blackens, while dry rot will have the ‘fruiting’ fungal growth at the surface. Both are caused by damp, but more-damp allows wet rot.
Although I’m not an expert on this by any stretch of the imagination.

 

[MARK.B.]

You may well be right Dave or is it dried out wet rot

 

[Adam W.]

It's what wasps leave their overwintering larvae in. Sometimes you'll find a grub inside the woolly pipes.

Just scrape it off and bin it if it bothers you.

 

[baldkev]

Looks like woodworm holes in the top right quadrant

 

[KimG]

Looks more like some kind of larvae silk cocoons, various kinds of insects have cocoons similar to this, I often find clusters of moth cocoons in nest boxes when I do the annual cleanout. Pretty sure it's not fungus of any kind. Post it up on an entymology forum, I bet they'll know.

 

[Old Grizzly]

I have seen very similar structures in musical instruments [organs, concertinas accordions and the like], where they are empty cocoons of what are commonly known by restorers as 'Pad Moths'.
I suspect there are many different species of moth and other insects that leave similar evidence behind them. I have never seen wood damage from this source.
OG

 

[croft36]

Looks like woodworm holes in the top right quadrant

Yes there is some woodworm holes.

 

[croft36]

I have seen very similar structures in musical instruments [organs, concertinas accordions and the like], where they are empty cocoons of what are commonly known by restorers as 'Pad Moths'.
I suspect there are many different species of moth and other insects that leave similar evidence behind them. I have never seen wood damage from this source.
OG

I had always thought that it was some kind of insect or such like, eg moths. I am pretty certain it is not wet or dry rot, it is something that has been ‘deposited’ on the surface, it does readily brush off.

 

[jonbee56]

Looks like a type of moth larvae. I’ve seen similar in bee hives and it’s classed as wax moth.. but not 100% certain

 

[heimlaga]

Wasp cocoons

 

[croft36]

I have never been able to establish what this is?! It is of a woolly texture and I usually find it between sheets of wood or plywood stacked close together in a slightly damp shed. This example is from underside of a wooden trunk which has stood on wooden shed floor fo many years. Any ideas please?
View attachment 129185

I can believe that but I am still puzzled that some pieces of wood have effectively been stuck together very close to each other!?