These caterpillars have taken over a branch or two of a small Nuttall Oak. Before I destroy them, any guesses as to what they are (and if they are basically harmless loiterers?
CLOSED: What lovely creatures might these become?
Could be young caterpillars of the Yellownecked Caterpillar, Datana ministra http://www.ag.auburn.edu/dept/entplp/bulletins/leafeatingcaterpillars/photo1.htm which becomes the moth shown in this site
Thanks - the second link indicates their defoliation damage is minimal, so maybe I'll let 'em stay ;o) They are weird little critters - if you blow on them, they all "rear up" on their back legs...
A show I saw on HGTV mentioned this kind of behavior. It's to make them look like one large organism when they all do that behavior. To keep birdies from thinking they are big enough to eat that 'huge' animal.
This behaviour is common among sawfly larvae. And my first thought was that these were sawflies. It was by searching for Sawfly and Oak on the net that I found a site on caterpillars that feed on trees and shrubs, http://www.ces.ncsu.edu/depts/ent/notes/O&T/shrubs/note07/note07.html which includes several sawflies as well as caterpillars like these. Checking further the species that mentioned oak led me to your caterpillars.
Your good Ken. I looked and didn't get very far. Hairstreaks & Sister butterflies will also eat on oak but I knew it wasn't one of them.