In 1860 Dr. Clemens described this pretty moth in the Proceedings of the Academy of Natural Sciences, Philadelphia, and since then it has been written on by Mr. P. Gennadius in the American Naturalist for January, 1874, and in the same year by C. V. Riley, in his 6th Missouri Report. It is well figured in the accompanying cut figure 6 (after Riley), in all its stages; a shows the larva, b the cocoons exposed by removal of the bark, c the moth, and d the chrysalis.