Varietal Resistance of Rice to the Green Rice Leafhopper, Nephotettix cincticeps Uhler

Experiments were conducted to select the new varieties and or/lines of rice resistant to the green rice leafhopper, Nephotettix cincticeps Uhler, and to evaluate the nature of their resistance to the insects in connection with the antibiosis and feeding and ovipositional preferences. The materials tested in this study were the varieties and or/lines of rice mostly proposed by the International Insect Resistance Nursery of IRRI and some others also orginiated from IRRI. Out of the 48 varieties and or/lines the 9 were selected as resistant and the 11 as mderately resistant. They have high antibiosis to the insects, showing significantly higher nymphal mortality and less adult emergence in the resistant and moderately resistant ones than the susceptible and moderately susceptible varieties Jinheung and Tong-il. Feeding perference was significantly different between the resistant and susceptible rice plants, resulting in much lower on resistant ones and much higher on susceptible ones. Ovipositional preference, however, was not different at all between the resistant and the susceptible ones. The nature of varietal resistance of rice to the green rice leafhopper seemed to be surely associated with the antibiosis and non-feeding preference.