What kind of Caterpillar?

Asked September 13, 2018, 5:37 PM EDT

Hello, my daughter and I just moved to SD and have found a few of these VERY LARGE caterpillars and I can't seem to find anything online that looks similar. I want to know about them since I've never seen anything similar and I keep finding them.
It had a one horn on the top of its head in case that cannot be seen in the pictures.

Codington County South Dakota

4 Responses

That is the caterpillar for the white lined sphinx moth - a common large hawk (aka hummingbird) moth in this area. The caterpillars can be varied in color - from green to the patterns you're seeing. At this stage, these are big enough that they are looking for somewhere to pupate.

No, not the white-lined sphinx. That is a larva of the spurge hawkmoth, Hyles euphorbiae. A close relative, the spurge hawkmoth is an introduced species, released into a number of states to combat leafy spurge. The larvae are also variable, but the red stripe down the back and the arrangement of light spots is very diagnostic to this species. They will wander great distances away from the host plant before pupation, I've often seen them crossing roads. I've attached a photo of one on leafy spurge.

Thank you! This was very helpful