1-2 cm tubes build with silt particles.
No interactions present.
I think these are the cases of the caddis Limnephilus vittatus, which breeds in pools and lakes that dry up, or considerably diminsh over summer
Ian Wallace, UK Trichoptera Recording Scheme
Thank you for the comment. Very interesting subject.
Lat/Lng: 57.4435, -2.346
OS grid ref: NJ793392