This species was described by me in the Cincinnati Quarterly Journal of Science, v. 2, p. 119, and it was said to feed upon the leaves of Ambrosia trifida, in the larval stage. Afterwards, in a note in the American Entomologist, I suggested that as it had only been bred from a collection of leaves of that plant, and had not actually been seen feeding, and as some species of Bucculatrix sometimes crawl away from their food plants to pupate, it was possible that it might turn out that this larva did not feed upon Ambrosia. This summer, however, I have been fortunate enough to find the larva mining the leaves of A. trifida, and also of several varieties of Helianthus; indeed it is much more numerous on Helianthus than on Ambrosia. Lithocolletis ambrosiœella and L. helianthivorella feeding on the same plants, many would consider only varieties of one species; as also many would consider Tischeria ambrosiœella and T. heliopsisella, which feed on the same plants, and on Heliopsis, varieties of one species.