Some years ago, Dr. Erwin F. Smith called attention to the fostering of this aphis by a species of ant, Lasius claviger, and, although not able to actualiy witness the act, his studies of the actions of this ant about the roots of peach trees infested by this aphis led him to believe that the former brought the latter from below ground in spring and placed them upon the twigs, thus indirectly if not directly causing their diffusion in orchards.