The preceding part under this title was published in 1945 (Can. Ent., 77:204-208). The species discussed at this time are chiefly from Oregon, where they were collected by my friends, Dr. James A. Macnab and Mr. Kenneth M. Fender, to whom I am indebted for the privilege of retaining the type materials. Dr. Macnab and Mr. Fender are engaged in detailed studies of this most interesting part of the Coast range and already have added vastly to our previous knowledge in many groups of insects.

Larval descriptions are useful, but if these same descriptions can be satisfactorily tied together by an artificial key, their value is greatly enhanced. Herewith a key is presented for the determination of mature geometrid larvae on which notes have been published in this periodical since 1941.

Macrocentrus gifuensis Ashm. a braconid of the subfamily Macrocentrinae is a parasite of the European corn borer, Pyrausta nubilalis Hubn., in both Europe and the Orient. It was introduced into America as a possible agent in the biological control of this pest. It has been bred in the laboratory for release by the author over an extended period, during which time comprehensive data on its life history have been accumulated (Wishart, 1946). Eggs are laid in the immature corn borer larvae and their polyembryonic development has been adequately described by Parker (1931).

This paper is a revision of the North American species of the genera Leschenaultia Robineau-Desvoidy, Parachaeta Coquillett and Rileymyia Townsend as they occur north of Mexico. Eight species have been recovered from this area and many more occur in Mexico, the West Indies and South America.