Forgive me for asking, but is this happening right at the soil line? If so, are you sure the plant isn't potted too deep and the bark rotting off?

There are a lot of ways to kill them. If you don't want to use a chemical soil drench like the long-acting Benomyl (serves also as a fungicide)/pyrethrin/imidacloprid, you can mix a small amount of an organic insecticide like pyrethrin or even a little Sevin with a mashed banana, which they will flock to (a flock of pill bugs? Lol) in a metal bottle cap or other small, shallow container on top of the soil or near the bottom of the plant - wherever the bugs congregate, but please be sure to use your best judgment if you have children or pets.

Al

Erin..if it was my citrus, I'd discard the compost, then hose roots/stems/trunk until all signs of Roly-Poly's and compost are gone.
Hose the container if you're planning on reusing. Add a couple drops of dish soap, then rinse.

Repot in fresh, well-draining soil or gritty mix, some people are using. As long as the mix is fertile but well-draining, it doesn't matter which medium you choose..

You want to rid Roly-Poly's. Are they in your home? I don't know if they eat roots/bark, but even if they don't, I doubt you want them in your plant or home.

I've never heard these crusted/shelled?-creatures eat bananas, but they like beer..lol..You can pour a litte beer or squashed banana inside an upsidedown container cap.
The food/liquid will attract them, goodbye Roly Poly. lol.

I'm assuming your citrus is indoors this time of year, right? since you're in z6B.

Wish I had an answer what can be done regarding the bark. How much is gone? Toni

There is nothing that you should do to 'repair' the damage to the trunk of the tree. That's one of the tasks that is best left up to the devices of the plant, itself. Often, using a sealant of some kind results in slowing the 'healing' process, in keeping the wound area too moist, and in sealing IN disease organisms.

I'd suggest that you use food grade diatomaceous earth (DE) sprinkled liberally over the surface of your citrus. It will not harm the tree, not harm you nor your family. It's not a toxic chemical.

It really does control critters like your pill bugs. Your choice of potting medium attracted them in the first place, for certain. If it's your own compost, you introduced them! Yikes!

toni, much to my horror I had a pill bug infestation in my collection of bonsai some years ago. All of them were planted in a bonsai mix composed of turface, grit, and bark. Not exactly a pill bug destination, lol.

Hi Rhizo. Erin asked, if he/she should add extra 'compost' or repot in regular potting soil.

To me, the definition of compost is old fruit, poop, etc, tossed in an outdoor bin.

Using compost from a bin would not only invite Roly Poly's, but long-legged, short-legged, beady eyed/long tail rodents and many other creatures in a pot. Yuck.

You bought packaged bonsai soil and found Pill Bugs? That's awful. Hope you returned this mix, and asked for a refund not an exchange..lol

I just spent a few days researching these bugs, actually on how to raise them. They like moist, dark places with decaying matter to feed on.

I read they rarely go after live plants, and if so, very little damage to the fine roots.

If they are getting after the bark on the plant, then there's a good chance , as Al suggested something else is wrong. There's a chance they are just taking advantage of it and not really doing the damage.

JoJo

Toni, about the bonsai mix...I didn't buy it, but made it myself. The crustaceans weren't in the components, but a routine part of the outdoor environment where I had constructed block and board shelves for the bonsai. They climbed up the shelving from the ground.

These little animals will certainly feed on tender roots and shoots and foliage. I've not observed them eating the bark from woody plants, but am not going to nix the idea. They are called 'woodlice', after all. ;-)

Erin should do some good investigation of this plant to make sure that rot isn't the problem as suggested earlier. The addition of compost could very well have decreased the fast drainage essential to healthy citrus (and other plants).

Rhizo..I've never seen RP's climb up..they're either on the ground, 'damp soil' or hang around hardy ferns..mwhere it's also damp.

Good point, Rhizo..if they're called Woodlice, most likely wood is part of their diet. Or a place to live.

From Wiki: They can live up to three years..kids keep them as pets..Owners of Tarantulas keep RP's as cage cleaners..they eat feces, mold and leftovers...leftover what? lol.
It also says, keeping RP's as pets require a moist habitat with limited light.

So, that makes sense. Soil can be kept moist and dark. Perfect environment.

I have gotten them in my orchid mixes. They like sphagnam moss. I drown them before bringing my plants back inside. Stick the plants in a bucket of water for a few hours. But, you need to cover the entire plant in the bucket. They will climb up on the top of the plant and survive. You need to immerse the entire plant.

They will nibble on roots but I've never seen any damage to the plant itself. Creepy critters!

Jane