Subject: catapillar species?
Location: Fullerton, California
August 15, 2017 6:37 am
Have found several of these on a California native milkweed, Asclepias fascicularis. They are quite sedentary and don’t seem to be eating the leaves or flowers. They are hard to photograph clearly, as the ‘skin’ is oddly transparent.
We do not recognize your caterpillar, and unfortunately, searching online for caterpillars on milkweed leads to Monarch Butterfly Caterpillars, which this is clearly not. We will attempt to research this further, but meanwhile, we will post it as unidentified. Perhaps one of our readers will recognize it.
Ed. Note: August 16, 2017
Thanks to a comment from Cesar Crash, we agree this is most likely the larva of a Syrphid Fly (see BugGuide ) which would mean it was probably feeding on Aphids.