While watering my River Birch tonight, I jumped out of my skin when I saw this guy. Can you see him in the picture? He was SO big, I almost put a leash on him and took him for a walk. He really is beautiful - kind of translucent green, about 2 inches long and as think as a ball park frank! At first I thought he might be one of those tomato horn worm, but no horns and way bigger then I've seen before.
Any ideas if he's a good guy or a bad guy?
Another look....
Last one....
Hi Gardengirl,
I remember seeing a pic of that cat in my Audubon guide to insects. It looks like a Polyphemus Moth. Here's a link to the USGS Moth page for this species: http://www.npwrc.usgs.gov/resource/distr/lepid/moths/va/955.htm
I think he's a friend. One or two aren't really going to damage your birch tree.
Mark
He is a cousin of the Tomato Horn Worm, being the caterpillar of one of the Sphinx Moths in the family Sphingidae. There are a number of species with pretty similar caterpillars, but since it is on a birch, it could quite easily be a caterpillar of the Big Poplar Hawkmoth Pachysphinx occidentalis http://www.silkmoths.bizland.com/pocciden.htm
I have to agree that it looks like a Polyphemus moth. They do eat Birch too. Someone just posted a pic of one they found the other day and I had looked it up. This one doesn't appear to have the little horn on the back like the Sphinx moth cats.
You should bring it inside and feed it and then keep it and see what it is!
I think you got it! It definitely looks like the Polyphemus moth. Normally, I'd take it and put it in my bug cage and keep it until it emerges, but we're going on vacation next week so I'll let it be free. Thanks so much for helping me ID it!!
GG
