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

Abstract

The rice leafroller,Cnaphalocrocis medinalis(Guenee),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.