A method of mass-rearing the rice leaffolder Cnaphalocrocis medinalis (GUENEE) on corn seedlings was examined and compared with the rice seedling method. Two important advantages were found in corn seedlings; 1) The cultivation of seedlings was simple and quick, and did not require special lighting. 2) The pupation rates and pupal weights were higher. As a result, the number of eggs deposited per female was also higher.