不同寄主植物上灰飞虱种群生命表的比较

为比较不同寄主植物上灰飞虱种群发展趋势，通过室内实验，组建了灰飞虱Laodelphax striatellus Fallèn在武育粳3号、盐稻8号、徐稻3号、Ⅱ优084、Ⅱ优42、扬麦12、稗草和千金子这8种寄主植物上的实验种群生命表；通过田间调查，比较了粳稻武运粳7号和籼稻Ⅱ优084上灰飞虱自然种群发生动态。不同寄主植物上灰飞虱实验种群生命表的比较结果表明，灰飞虱的若虫发育历期在稗草上最短，其次为扬麦12和粳稻上，而在杂交籼稻Ⅱ优084、Ⅱ优42和杂草千金子上的发育历期长达近30 d；灰飞虱在稗草上的种群趋势指数亦最高，为45.57，其次为粳稻品种盐稻8号（39.36）、徐稻3号（34.54）和武育粳3号(31.70)上，其中盐稻8号与稗草上无显著差异；杂交稻Ⅱ优084和Ⅱ优42上灰飞虱的种群趋势指数显著低于粳稻上的；而灰飞虱在千金子上的种群趋势指数最低，仅为11.04。大田调查则表明，一定时期粳稻武运粳7号上灰飞虱种群个体数量显著高于籼稻Ⅱ优084上。研究表明灰飞虱的适宜寄主植物依次为稗草、粳稻品种和小麦。

Comparison of the life tables of Laodelphax striatellus (Homoptera: Delphacidae) on different host plants

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.