I was visiting my mom in coastal Virginia and her iris have a bizarre problem. Hundreds of them have been bitten--really looks like large teeth marks by a very small mouth--at the very base of the leaves, so the leaves are lying on the ground, some completely severed, some only halfway, some with a half-moon shaped bite at the edge, the size of half-a-nickel. What on earth can be doing this? She's frantic, as they all came from my grandma's garden. Thanks in advance for helping to ID the culprit!! (We haven't checked the tubers yet--too hot outside)