Pests in an old house

[Claes gyll]

Hello.

I have found some kind of pest in an old house I am going to renovate. The house was built in the 1930s. Summer guests have stayed there for the past 30 years, and it hasn't been heated in the winter.
The structure is made of studs, the insulation is peat, and there is no air gap.

Inside the house, the walls were covered with masonite boards. When I removed these, there were some cocoon-like things on the wall. The cocoons were attached to the wooden panel and felt papery and empty inside.

Does anyone know what has gotten into the house?

Thanks in advance,
Claes

 

[MissAnpassad]

Prod them and see if anything crawls out. Had something similar in the storage room and there were spiders in them.

 

[Allinug]

Hoplodrina octogenaria maybe?

Don't believe it's spiders because of the puppy-like shape. Spiders usually lay eggs in round cocoons.

 

[MissAnpassad]

It's not the egg sac I mean, but the one they spend the winter in.

 

[Mattias_Eson]

I had the exact same pests in my old garage. They had "glued" my drywall to the wall with their cocoons.

I have no idea what they are, but they hadn't damaged any of the materials (apart from being stuck like hell).

 

[Nick4]

Looks like bird cherry ermine larvae (puppae), there can be quite a few if you have a bird cherry tree in the yard....

 

[mf76]

The first picture looks exactly like the empty cocoons I had isolated behind the fascia boards. It was wild bees that built them at my place. I found them in all variations from empty cocoons to larvae to almost complete bees. And had plenty of angry adult bees doing their best to get rid of me.

 

[Oldboy]

There are plenty of those with us too. On boards and planks, etc., in outhouses and the like. Annoyingly, I don't know what it is.

However, I am quite convinced that it is not pests causing trouble for the houses. So I don't care about them specifically. I'm just annoyed when I have to use a board or plank and have to remove them since they are fairly stuck. However, it is usually easy with a chisel or screwdriver or putty knife to scrape them off.

 

[Johnny Glader Hellebladh]

Bee moth (Aphomia sociella)

 

[Chrisch]

Glad I found this thread, now I know what I have found, as tough as it gets, a relatively large yellowish larva that has left the sticky stuff, bumblebee moth. Phew, I thought it was a house longhorn beetle when I saw the larvae.