Subject: What is this chunky boy?
Geographic location of the bug: Southern Utah, Kane County
Time: 01:29 PM EDT
Your letter to the bugman: Hi! I’ve have looked and looked but cannot definitively identify this caterpillar I found a couple days ago. It was in a cottonwood tree. My first thought was a tomato hornworm but the side spots and horn seem too different. Thoughts?
How you want your letter signed: D. E.
Though this is not a Tomato Hornworm, it is a different species of Hornworm from the family Sphingidae. We believe it is the Big Poplar Sphinx caterpillar based on the species found Sphingidae of the Americas Utah page. According to Sphingidae of the Americas: “Larvae feed on cottonwood and poplar (Populus) and willow (Salix).”