I regret that I do not (yet) have any photos of the adult moth (Artace cribrarius), mostly because it strongly resembles a stuffed animal, but please enjoy these fascinating pictures of the A. cribrarius caterpillar, a very well-camouflaged caterpillar which appears to resemble the bark of a birch tree, complete with nifty “fringe of sublateral hairs” around its base. When startled, it lies flat against whatever it’s on, hiding its head and its legs under the fringe and really, really strongly resembling the bark. (Bugguide calls it a “twig mimic”, but I think this is more trying to be part of the tree trunk than a sticking-out twig. Either way, it is pretending to be wooden!)
This is a fairly large caterpillar, about 3cm long, and one of only two species in the genus Artace to be found in North America. “Dot-lined white” apparently mainly describes the gorgeous, spotted white wings of the adult moth, although it also sort of describes the caterpillar.