Whitemarked (Yellow) Tussock Moth Caterpillar
I didn’t see this guy on your site. I came across it on a stinging caterpillar website. I’m glad I didn’t know it could sting when it was on me! I was gentle with it though and had no irritation after photographing it and shooing it away. These pictures were taken along the Brandywine River in PA in Jun 2005.
We actually have many photos of White Marked Tussock Moth Caterpillars, Orgyia leucostigma, on our site. We suspect you never checked our five caterpillar pages.