Just wanted to follow up on this. My individual at BugGuide.net was identified as a Rose Hooktip caterpillar: bugguide.net/node/view/315396
Seabrooke
05-Aug-2009 01:53
Don't suppose you ever got an ID for this guy? Just searched the web for a match to a caterpillar I had, and this was the only brown furcula photo to come up - and it turned out to be yours, taken just up the road from my caterpillar! A new Furcula sp. for Ontario, perhaps? :) Am also submitting to BugGuide.net