A laboratory study was made on the interactive effects of temperature (20 degrees C, 23 degrees C, 26 degrees C, 29 degrees C, and 32 degrees C) and nitrogen fertilization level (0 and 250 kg x hm(-2)) on the survival, development, and reproduction of brown planthopper (BPH) Nilaparvata lugens. With increasing temperature from 20 degrees C to 29 degrees C, the egg hatchability, nymphal survival, and adult fecundity of BPH increased and the developmental duration of all stages shortened; while at 32 degrees C, it was in adverse. At all test temperatures, the BPH on rice plants treated with 250 kg N x hm(-2) had higher egg hatchability, nymphal survival and adult fecundity, and shorter developmental duration of eggs and nymphs, compared with no nitrogen fertilization, which suggested that high level nitrogen fertilization enhanced the ecological adaptability of BPH to stress conditions. There were significant interactive effects of temperature and nitrogen fertilizer on the egg hatchability, nymphal duration, and adult fecundity of BPH, implying that global warming and long-term high level application of nitrogen fertilizer could be responsible for the outbreaks of BPH in recent years.