We found these two bugs on a hosta plant. They have a mosaic design belting the exposed part of the body. The belt is white and black. The black being a border for white “spots” – one sequence of “spots” depicts a butterfly design. I wish I had had my 5D camera instead of only the NexusOne cell.
Your insect is a moth…Ailanthus Webworm Moth.
They are found over most of eastern North America.
The adults feed on nectar of various flowers. The caterpillars are found in webs in Ailanthus (tree of heaven) and paradise trees. The caterpillars may also feed on other deciduous trees and shrubs.
The Ailanthus tree is not native and is invasive. The insect is native…but it has learned to like this invasive tree….a good thing!