We LOVE your site and use it regularly. We also have it linked on our greenhouse/nursery website to encourage our customers to i.d. and learn about bugs rather than freaking out, pouring chemicals on them and otherwise engaging in Unnecessary Carnage. Your site is a fantastic resource — educational and entertaining! So anyhoo, the lumps on this pin oak tree were spotted this afternoon by one of our fellow treehuggers. Upon closer examination, we all had to rub our eyes a couple of times to be sure we weren’t seeing things and confirmed that they were two pinky finger-sized caterpillars perfectly matched to the smooth gray bark of the immature pin oak. When they were still they looked just like part of the tree trunk, and we had to touch them before they began slowly making their way down to the bottom of the trunk headfirst. They had a soft fringe all the way around their bodies — I wish my photo was clearer. They were the coolest dang bugs I’ve seen in a long time. The closest thing I can find on your site is an underwing caterpillar, but the one you have matches a corkier bark. Are their different species that match different trees? Oh yeah, we’re a few miles south of Lawrence, Kansas, as the moth flies. If you can help us out between photograms, we’d be much obliged. Your friend,
We agree with your assessment that these well camouflaged caterpillars are Underwing Caterpillars in the genus Catocala, but we are at a loss for the exact species. BugGuide has over twenty images of Underwing Caterpillars posted.
The pair of “underwing caterpillars” are actually two larvae of the “large tolype” moth, Tolype velleda. Very striking, aren’t they!