Subject: What is this larve?
Location: Near Lyle, WA
April 25, 2016 6:38 pm
We found this along a trail in eastern Washington. It was as burrowing a hole in the dry dirt. I tickled its tail with a piece of grass and it turned around, half in and half out of the hole, as seen in the pic. About 3-4 inches long, as big around as my pinky finger.
We are very excited to post your image of a Pacific Green Sphinx Caterpillar, Arctonotus lucidus, which we identified on The Sphingidae of the Americas site. Caterpillars of Sphinx Moths are usually easy to identify because they have a caudal horn, but some species lose the horn and only a caudal bump remains, and it is thought to afford some protection as it resembles an eye. Though we have several images of adult Pacific Green Sphinx Moths on our site including this individual from Lyle, your caterpillar image is a first for us. David Wikle is quoted on The Sphingidae of the Americas: “and in the fifth [instar], the ‘eye of God’ is pasted on its arse and the horn is replaced by a raised area like Xylophanes or Eumorpha larvae.” The larva is also pictured on BugGuide. Since it was digging in the dirt, and it was quite large according to your description, we can deduce it was going underground in preparation for pupation. We are going to copy Bill Oehlke as your image is so stunning, he may request permission to post it to his own site.