K. K. M. Myint, H. Yasui, M. Takagi and M. Matsumura. Viru- lence of long-term laboratory populations of the brown plan- thopper, Nilaparvata lugens (Stål), and whitebacked planthopper, Sogatella furcifera (Horváth) (Homoptera: Delphacidae), on rice differential varieties. Applied Entomology and Zoology, 2009, 44: 149-153.