Effects Of Different Rice Varieties On Growth, Development And Adult Flight Capacity Of Cnaphalocrocis Medinalis(Guenee)

The rice leaffolder, Cnaphalocrocis medinalis (Guenee), is an important long-distance migratory rice pest. There have been frequent and serious outbreaks of this pest in recent years which causing huge losses to rice production. Deterioration or inadequacy of larvae foodstuffs conditions not only affect insect growth and development, but also could easily cause the adult reproductive diapause and induce of insect migration. There are six major rice growing areas in China planting with different main cultivars, in particular, high-yield, high-quality super rice have been widely planted in recent years, would this significant phenomenon affect the occurrence regularity and migratory behavior of Ieafroller has not yet been reported. Based on this, developmental durations, survival rates, pupal weight, adult fecundity, ovarian development, and flight capacity of C. medinalis feeding on six different rice varieties were investigated to determine the influences of host quality in larval stage on the development, reproduction and flight ability. These rice varieties were Wuyujing3(japonica rice), Ningjing1(hybrid japonica rice), TN1(indica rice), Shanyou63(hybrid indica rice), Liangyoupei9(super hybrid indica rice), and Yongyou9(super hybrid indica crossed japonica rice). The main consequence are followed:1. It shows a significant effect of different rice varieties on the growth and development of C. medinalis. The C. medinalis feeding on Wuyujing3and Ningjing1have slower growth rate, lower survival rate, lighter pupas, longer pre-oviposition period, shorter oviposition duration, and higher fecundity comparing to those feeding on Yongyou9and Liangyoupei9, the japonica rices are not conducive to the growth and reproduction of the Ieaf roller.2. There are significant influences of different rice varieties on the female ovarian development. The ovarian development level of C. medinalis feeding on japonica rices is lower than that feeding on super hybrid varieties, the japonica cultivars are completely to the disadvantage of ovarian development. 3. The C. medinalis flight capability shows significant difference that feeding on various rices. These will flght faster and longer that raised on japonica rices which have contributed to induing migration.4. Most of the nutrient contents of different tillering-leaves are significantly different. Yongyou9contains less riboflavin, pyridoxine, niacin, folic acid, cyano-cobalamin, ascorbicacid, vitamin A, vitamin E, protein, magnesium, phosphorus, calcium, manganese and total amino acid content, but more Thiamine, pantothenic acid, sodium, potassium, zinc, copper, palmitic acid, linoleic acid and moisture content than Ningjing1, some other contents show no significant difference.The results can provide the foundation for C. medinalis population forecasting and the development of sustainable management tactics, as well as the mass and continuous rearing on synthetic diet.