Subject: SE Arizona Caterpillar
Location: Patagonia, AZ
September 6, 2014 6:01 pm
Greetings! We found 2 of these enormous caterpillars making free with our two grape vines today. We are located in Patagonia, AZ, about 4,000 feet, and today is September 6, 2014. When we removed them from the vine, the exuded a bright green slime. Folks around here say these are hornworms, but they don’t look like any example I can find, and do not have a horn. Would love to know what these really are.
Signature: The Schonemans
The folks around there who told you these are Hornworms are correct, but they are atypical Hornworms known as Achemon Sphinxes that loose the caudal horn during the final molt between the fourth and fifth instars, and instead of a caudal horn, they are left with a caudal bump or caudal eye. Prior to shedding the horn, the Achemon Sphinx Caterpillar sports a prominent, curved horn that is significantly longer and thinner than the horn of most Hornworms. According to the Sphingidae of the Americas site: “Eumorpha achemon larvae feed upon Grape (Vitis), Virginia Creeper (Parthenocissus quinquefolia) and other vines and ivies (Ampelopsis). Larvae get quite large and occur in both a light (green) form, a reddish-orange form, and a darker (tan/brown) form.”
Awesome!! I will share this info and thank you so much for the quick response!!