不同水稻品种对稻纵卷叶螟生长发育、存活、生殖及飞行能力的影响

系统研究了稻纵卷叶螟在6种不同水稻品种(常规粳稻武育粳3号,杂交粳稻宁粳1号,常规籼稻TN1,杂交籼稻汕优63,超级杂交籼稻两优培九,超级杂交籼粳稻甬优9号)上取食后的发育历期、存活率、卵巢发育进度、繁殖力和飞行能力.结果表明,武育粳3号和宁粳1号能显著延长稻纵卷叶螟未成熟期的发育历期,降低其存活率,延缓卵巢发育进度,降低成虫繁殖率,并提高成虫的飞行能力；不同水稻品种间的影响存在显著差异,其影响从大到小排列为杂交粳稻＞常规粳稻＞常规籼稻＞杂交籼稻＞超级杂交稻.这说明,幼虫期营养对稻纵卷叶螟的生长发育、存活、生殖和飞行能力具有显著影响.

Effects of different rice varieties on larval development, survival, adult reproduction, and flight capacity of Cnaphalocrocis medinalis (Guenée)

The rice leafroller, Cnaphalocrocis medinalis (Guenée), is an important rice pest in the main rice-growing areas of China. In recent years, it has caused substantial damage and seriously threatened rice production. C. medinalis is a seasonal and long-distance migratory species; its flight behavior is probably affected by many environmental factors, such as food quality during the larval stage, population density, photoperiod, and weather. Deterioration or shortage of food during the larval stage not only influences the development of C. medinalis but can also cause reproductive diapause to induce its migration. To determine how larval host quality affected development, survival, reproduction, and flight ability, we investigated larval survival, adult ovarian development, fecundity, and flight capacity of C. medinalis feeding on six different varieties of rice. The varieties were Wuyujing 3 (japonica rice), Ningjing 1 (hybrid japonica), TN1 (indica), Shanyou 63 (hybrid indica), Liangyoupei 9 (super hybrid indica), and Yongyou 9 (super hybrid indica × japonica). These six varieties were the major ones cultivated in different rice-growing areas of China. Development, survival, and fecundity of C. medinalis on the different rice varieties were observed by determining semi-natural population life tables on each variety. Ovary development and the flight abilities of adults feeding on different rice hosts were investigated by dissecting the female ovaries and by tethered flight tests, respectively. The results showed that C. medinalis exhibited significantly lower survival in the immature stage and significantly lower adult fecundity when larvae fed on Wuyujing 3 and Ningjing 1 than when they ate Yongyou 9 or Liangyoupei 9. Similarly, the larval and pupal developmental stages of C. medinalis larvae that used Wuyujing 3 and Ningjing 1 as hosts were significantly longer compared to those that developed on Yongyou 9 and Liangyoupei 9. Furthermore, the average ovary developmental grades of C. medinalis from Wuyujing 3 and Ningjing 1 were significantly lower than those from Yongyou 9 and Liangyoupei 9 in both mated and virgin moths. Conversely, both mated and unmated 3 and 4 day old adults had significantly higher flight abilities when they had fed on Ningjing 1 as larvae than those than had fed on other rice varieties. The results indicated that the different rice varieties significantly influenced the survival, development, reproduction, and flight abilities of C. medinalis. The rice varieties could be ranked in order of their negative influence on C. medinalis as follows: Ningjing 1 > Wuyujing 3 > TN1 > Shanyou 63 > Yongyou 9 > Liangyoupei 9. This paper discusses probable explanations for the observed differences in development, survival, fecundity, and flight abilities of C. medinalis. Leaf morphological characters, high cellular contents of silicon, and the thickness of the wax layer may be the major reason for the decline in fitness of C. medinalis feeding on japonica rice varieties. In addition, a shortage of some amino acids and low levels of juvenile hormone resulting from low-nutrient or deteriorated hosts may inhibit ovary development and contribute to the migration of C. medinalis. These results could provide the foundation for C. medinalis population forecasting and the development of sustainable management tactics.