Giant orange caterpillar
August 29, 2009
Can you identify this caterpillar? Seen in eastern PA on a canal towpath in August, length about 4″, width over .5″.
Unless this is an irradiated mutant, we doubt that the Argid Sawfly Larva you found was 4 inches long. Argid Sawflies are not Caterpillars, but are non-stinging relatives of wasps. We cannot tell you the exact species, but we are linking to an image on bugguide that looks similar to your example.