When larvae and adults ofEmbaphion muricatumSay were offered 31 types of seeds (from 28 species of plants), both stages almost always preferred seeds of introduced species more than those of species native to North America. Wheat, hulless oats, and rye were the most preferred by adults and larvae of all seeds offered. In greenhouse tests with 5 of these seed varieties, rye and wheat were preferred and were more heavily damaged than oats, barley, or soybeans. Soybans, however, were damaged to a much greater extent in greenhouse tests than in laboratory tests.