There are several good books you could get to help you ID the caterpillars you find. One is Caterpillars in the Field and Garden which is a field guide to the butterfly caterpillars of North America by Allen, Brock and Glassberg. Once you learn what your local butterfly caterpillars look like, then at least you'll know not to squish them. If you're in the east, another good book is Caterpillars of Eastern North America by David Wagner - this is mostly moth caterpillars. I'm sure you'd want to save any big silk moth and most sphinx moth cats. Then everything that's left is probably a pest, especially if it's tent caterpillars. I'm glad that yellow-billed cuckoos show up here every year just when the outbreak of tent cats is beginning! Another helpful book is Garden Insects of North America by Cranshaw - this book IDs a lot of butterfly and moth caterpillars, plue other larvae like sawflies that eat leaves. Another way is to take a picture of the offending leaf eater and post it on this forum - we may (or may not) know what it is. I don't blame you for wanting to protect your serviceberry. I've got a young amelanchier arborea that I just love - so far, no cats have found it. I figure the only ones I'd be likely to find on it would be either red-spotted purple cats or tiger swallotail cats, and I wouldn't mind having them - these two butterflies lay their eggs far apart, so no plant gets really ravaged by either of them. MissSherry

"Plant it and they will come." I started out by planting a few milkweeds late in the summer of 2005. I think I got them out too late for that year, but I had Monarchs show up here the next summer and raised 70 cats. Last year I raised over 500, so we were really busy last year releasing them here! They haven't shown up yet this year. If you have the milkweed planted and those butterflies are known to visit your part of the state, then what they have to do is find you and lay eggs on your milkweed. If you want to keep the butterflies there at your place (rather than them going elsewhere for food), make sure to plant nectar plants for them. Cathy

It's one of the color forms of the Imperial Moth, Eacles imperialis. Nice find, as we are more familiar with them in green or brown. I'll attach a picture of the gorgeous moth below. Here is a link that might be useful:

I believe your caterpillars are actually cutworms. 2005 has been a particularly bad year for them in my area (Kentucky). I hand pick them to get rid of them, or you can spray Bt if they're really out of control. They love brug foliage, and will make your plants look tattered in only a short amount of time. They will eat not only the foliage, but will eat flowerbuds, and chomp off entire leaves by cutting through the leaf stalks. I would get rid of them so you won't have even more of them next year. Here is a link that might be useful: Cutworm Information/pic