Ant killer usually lists woodlice on it. The spray kind.

Hi

the woodlice have moved in because it is damp/dark and safe to live they do little damage if any, just feeding from the decaying bark , sounds like you have another problem with the tree if the bark is dead or dying.

The woodlice have highlighted a problem but are not the cause

Poor old woodlice get the blame for everything. As you say Gnarly, they don't kill plants or trees, just recycle dead and decaying bits.

so true Cammomile

Gg

Agree with Cammomile and GG you have another problem with your apple tree which the woodlice have highlighted. They are totally incapable of eating healthy wood.

I know I suggested ant killer, but I have always liked woodlice. As little kid, I used to search for them in my Nan's garden.

We have an old house and they get in the bathroom via the side of the bath - then I kill them, or they crawl over the floor at night!