|Photo by Ned Harris 9/11/2015|
Thanks to Fred Heath for identifying these caterpillars as Bordered Patch larvae. (Click the link to see what they look like as adults.) Here, they are feeding on Canyon Ragweed (Ambrosia ambrosioides).
|Photo by Matt Ball 9/11/2015|
Matt and I saw them feeding on the equally yummy (to them) Common Cocklebur (Xanthium strumarium). The black dots you see are caterpillar poop, called frass by the experts.
Under the rubric 'more-than-you-ever-wanted-to-know', I'll tell you that frass comes from the German verb fressen - to eat, for non-human animals; if you use fressen to describe how a human is eating, you mean that the person is eating quickly, sloppily, 'like a pig.' (The verb essen is to eat.) Principle parts: fressen - frass - gefressen. (essen - ass - gegessen; The counterpart in English [a Germanic language, too] is also a strong verb: eat - ate - eaten.) One of the few times a PhD in Germanic Languages and Literatures comes in handy in the canyon, so I'll take it!