During studies on the aster yellows virus in the Niagara Peninsula of Ontario, the dryinid parasite Epigonatopus plesius (Fenton), has been observed since 1956 on the nymphs and adults of the six-spotted leafhopper, Macrosteles fascifrons (Stål). During 1956 adult females of E. plesius reared from this host were identified by Mr. K. V. Krombein of the U.S. National Museum, Washington, D.C. Dr. W. R. M. Mason (1957) Entomology Division, Ottawa, wrote, “This is a very rare species. There are only two collections in Washington and only yours in the Canadian National Collection”.