This is the scanned image of a bug I found apparently chewing holes in the leaves of my tomato plant.  I've consulted every gardening book I have and scoured the web and still cannot identify it. 

This guy is about 1/4" long (I found three smaller ones a couple weeks ago).  He has 6 legs and a small head on the underside of his body.  The head is at the top of this picture, and this is his underside.  He appears to have little delicate spines rimming the top of his body.  He's all green.  He carries this brown dried up material (bottom of picture) which is attached to his tail end.  He normally carries it over his back, but when you bother him he straightens it out.  He doesn't like being on his back and will arch to try to flip back over.

If you can tell me more about this bug, please email me at : ralleia@yahoo.com