Abstract: The life tables of small brown planthopper (SBPH) Laodelphax striatellus Fallèn on different host plants including five rice varieties (Wuyujing No. 3, Yandao No. 8, Xudao No. 3, Eryou No. 084 and Eryou No. 42), one wheat variety (Yangmai No. 12), and two weed species (Echinochloa crusgalli and Leptochloa chinensis) were compared in the laboratory, and the population dynamics of SBPH on two different rice varieties was investigated in fields. The life tables of experimental population of SBPH showed that the nymphal duration on E. crusgalli was 23 d which was the shortest, while those on Eryou No. 084, Eryou No. 42 and L. chinensis were nearly 30 d. The index of population trend (I) of SBPH on E. crusgalli was the highest (I=45.57), which was not significantly different from that on Yandao No.8 (I=39.36), but significantly different from that on the other tested plants. Moreover, the index of population trend on indica hybrid rice such as Eryou No. 084 (I=20.46) and Eryou No. 42 (I=19.53) was significantly lower than those on japonica rice such as Yandao No. 8, Xudao No. 2 (I=34.53) and Wuyujing No.3 (I=31.70), and the index of population trend on L. chinensis was the lowest (I=11.04). Field investigation indicated that the number of SBPH on japonica rice Wuyunjing No.7 was higher than that on indica hybrid rice Eryou No. 084, while there was no steady difference of SBPH on the tested rice varieties in plots. The results suggest that E.crusgalli is the most suitable host plant of SBPH,followed by japonica rice varieties and then wheat.

Key words: Laodelphax striatellus, host plant, life table, index of population trend, population dynamics