As the rice leaf roller Cnaphalocrocis medinalis Guenée feeding onpotted rice,it is found that the survival of larvae and pupae,pupaweights,durations of pre-oviposition and oviposition,longevity,andfecundity of adults varied with different varieties,and developmentalstages of rice growing on different nitrogen levels,while the durationof immature stage of this insect was stable.A synthetic index forevaluating the food quality were then presented as follows: F(fitness index)=S (preference index)×I(population increaseindex) The results of feedi...
