Influence of resistant rice varieties to the population parameters of Nilaparvata lugens and Sogatella furcifera.

Population parameters of Nilaparvata lugens (BPH) and Sogatella furcifera (WBPH) were preliminarily compared under semi natural conditions, using 4 BPH resistant rice varieties, ASD7, IR36, JX89, and Mudgo. The results indicated that on these rice varieties, WBPH had higher reproductive rate shorter developmental time, and higher population increase rate than BPH did. The most resistant variety to BPH is JX89, and that to WBPH is Mudgo. Compared with the susceptible TN1, all these resistant rice varieties have different levels of resistance to the two planthopper species, suggesting that BPH resistant rice varieties are also resistant to WBPH, but WBPH is better adaptive to these varieties. It is suggested that if the BPH\|resistant rice varieties are released in a district for a long term, it will inevitably cause the outbreaks of the whiteback planthopper.