I hope you can help me…I found this caterpillar on my back porch in Prescott AZ. I am about a mile in altitude in the “high desert west”. I think it fell from some trees with that green material in the picture. I can’t figure out what it is. I am guessing it would sting me. Thank You,
This is some species of caterpillar in the genus Automeris. These are giant silkmoths. There are several possible species in Arizona, but none seem to match exactly. They include Randa’s eyed silkmoth or Automeris randa, and Cecrops eyed silkmoth or Automeris cecrops. A nearly identical image is posted to BugGuide with the possible identification being Automeris boudinotiana. Moths in the genus Automeris are known as the Eyed Silkmoths and some species have very localized populations. Automeris caterpillars do have stinging spines.