For many years American workers have applied the name Phanerotoma tibialis (Hald.) indiscriminately to specimens reared from a variety of lepidoprerous hosts pertaining to the genera Acrobasis, Carpocapsa, Grapholitha, Laspeyresia, Melissopus, and Tetralopha. Concurrently tibialis has come to be regarded as an unusually variable species in both structure and colour. Recently, after examining many specimens reared from the above hosts, I reached the conclusion that two species of Phanerotoma are involved, one a parasite of Pyralidae of the phycitid and epipachiinid groups, and the other a species that apparently confines its attacks to certain Olethreutidae of the subfamily Eucosminae. For reasons stated below it appears that the name Phanerotoma tibialis (Hald.) applies correctly to the species with pyralid hosts (Acrobasis, Tetrarlopha), whereas the species reared from Olethreutidae (Carpocapsa, Grapholitha, Laspeyresia, Melissopus) should he called Phanerotoma fasciata Prov.