We were thrilled to see this species, since it’s not one you can find here in western Montana. Achemon caterpillars may be tan or green, sporting diagonal elongated or segmented spots along the sides and a distinctive eyespot on the top of their hind end. Younger caterpillars have a “horn” on their hind end, but lose it after their fourth instar. They feed on leaves of grape (Vitis), Virginia Creeper (Parthenocissus), porcelain berry (Ampelopsis) and related vining plants. Overwintering as pupae underground, the gorgeous adults will emerge in late spring or summer, wowing us with their hummingbird-like flight as they sip nectar from flowers.  

Size: Larva up to to about 90 mm (3.5″); adult wingspan 87-96 mm

Photo by: Bri Wentworth on 8/27/21 in Billings, MT