The brown planthopper (Nilaparvata lugens (Stål)) and white-backed planthopper (Sogatella furcifera (Horváth)) represent two of the most important insect pests of rice in Asia, causing severe damage to rice production. Both belong to long-distance migratory insects but differ in the time when they reach maximum density during rice-growing season. S. furcifera generally reaches its peak of occurrence when rice is before the filling stage; while N. lugens reaches its peak at the rice filling stage. It is possible that the same rice stage might impact the two planthopper species differently, thus leading to such a seasonal difference in population growth. To test this, we inoculated newly-emerged adults onto rice plants at each of the three developmental stages, i.e., early tillering stage (about 40-d old, with 2-3 tillers), jointing stage (about 60-d old, the longest internode < 2 cm) and booting-to-heading stage (about 75-80-d old). The level of ovarian development and take-off rate were then measured daily from the 2^nd to the 5^th day and from the 1^st to the 5^th day after emergency, respectively. Ovarian development from 2^nd to the 5^th day was largely dominated by grade Ⅰ, Ⅱ, Ⅲ and Ⅳ, respectively, with three exceptions including the 4d- (dominated by grade Ⅱ) and 5d-old S. furcifera females (grade Ⅲ) at booting-to-heading stage plants, plus the 5d-old S. furcifera females (grade Ⅲ) at jointing stage plants. For ovarian development in N. lugens females, in vast majority of the cases the three rice stages showed comparable proportion of females at each of the detected ovarian development grades, we only observed significant difference between early tillering stage (73.2% of the females at grade Ⅳ) and booting-to-heading stage (89% at grade Ⅳ) on the 5^th day. In contrast, the grade of ovarian development displayed much larger differences among the three rice stages for both 4d-and 5d-old S. furcifera females. In particular, over 86% of the females from rice early tillering stage developed into grade Ⅲ on the 4^th day and into grade Ⅳ on the 5^th day, versus less than one quarter of the females from the booting-to-heading stage. To a similar extent, the ratio of females at grade Ⅲ was 4.2:1 between jointing stage and booting-to-heading stage on the 4^th day, along with a ratio of up to 6.8:1 between early tillering stage and jointing stage for the 5d-old females at grade Ⅳ. As for the take-off rate, while little variation was seen for N. lugens across the three rice stages, noticeable differences were revealed for 1d-, 4d- and 5d-old S. furcifera adults, with early tillering stage being constantly associated with the lowest take-off rate and booting-to-heading stage with the highest take-off rate. Thus, our results demonstrated a profound effect on the development of S. furcifera by a change of rice stage, as compared to relatively limited effect on N. lugens development. Furthermore, among the three rice stages, early tillering stage is most favorable and booting-to-heading stage is least favorable for S. furcifera development, a trend appearing to be reversed in N. lugens. Taken together, our analysis offers a plausible explanation for why the peak of S. furcifera comes before that of N. lugens.