For the last couple of years a Google search on "Large Moths" or "Large Moth" results in this as the top site - so, Welcome!
Examples of a large moth in my other galleries - My Moth Galleries especially, My Sphinx Moths If it is not there check these: Silk Moths or Sphinx Moths or Underwings or Carpenterworms The Cecropia is the largest moth in North America. The one below (second row) has a 6.5 inch wingspan.