The difference in food plants and seasonal life-history between beetles of the species Lema trilineata Oliv. in Manitoba and the same species in Eastern Canada and Eastern United States indicates rather strongly that they belong to different biological races. The belief was entertained for a time that the Manitoba beetle belonged to an entirely different species, but a series of adults sent to Mr. W. J. Brown of the Dominion Entomological Branch, Ottawa, proved to be identical with the eastern species.