well i must make this my very first post because because i found out first hand about these lil bastards, and i dont want you to have probs so maybe me adding this will bring on more advise because after what i seen you need to get rid of them. let me tell you what happend, my wife had broke a rose off so i cut it and i had some soil under deck from last year, so i put rose in it and had it on back deck and i seen a few roly's i thought oh i use to kick them too lol ... so next day i had a seedling that looked messed up(now it was not but about a day old maybe 1/2 inch in a pete puck, so i wanted it out but did not want to give up on it jus yet, so i took it out and just sit the pete puck on the soil beside the rose, i came back the next morning and holy crap there were 2 of them sitting on the seedling ! i was ok well it just a roly it be ok... well i come home that afternoon and they where all 3 gone 2 roly's and the seedling ! they ate all of it i could not find anything, so i just wanted to give this info. i dont know what effects they would have on larger plant but i know they can eat a seedling so im guessing they would have no trouble with roots, so i would say you need some help to get rid of them and find the way they got in. just my 2 cents

hope it helps