Eaten amaryllis bulbs?

I have over a 100 amaryllis and most have bloomed in past years. This year not many bloomed and I thought they were just too crowded or under fertilized. When I dug them up to move them, the liked as though they'd been eaten. Many of the layers of the bulb were showing like an onion. The soil around them was undisturbed so it wasn't squirrels or other animals above ground. Any ideas?

Here is what the damage looks like.

see reply on other thread... I think it's borers