Cnaphalocrocis medinalis is a key lepidopteran pest of rice.  However, little is known about the nutritional requirements of the adult or the effects of adult-derived nutrients on reproduction.  The aim of the present study was to evaluate the effects of carbohydrates and amino acids on the reproductive and demographic parameters of C.?medinalis.  Different feeding solutions significantly influenced adult survival and reproduction.  All the sources of carbohydrates used in the treatments (fructose, glucose, and sucrose) were sufficient to increase adult longevity and fecundity, and benefited the development of ovaries in the adult stage.  The positive impact of carbohydrates on lifetime fecundity was due to the prolonged oviposition period and the increased daily fecundity.  The intrinsic rate of increase (r_m) of C.?medinalis increased from 0.103 in water-fed individuals to approximately 0.138 when adults were fed with solutions containing carbohydrates.  In contrast, amino acid intake by adult insects exhibited no effect on the longevity, fecundity, ovarian development or population growth, even showing an impact of decreasing longevity of females.  As nectar secreted by the flowering plant is generally rich in sugars, the potential effects of nectar on the adults of C.?medinalis and other pests have to be considered during the development of biological control by applying flowering plants as a microhabitat and food source for natural enemies in rice fields.

Rice leaffolder, Cnaphalocrocis medinalis (Guenée), has become a major pest throughout the rice cultivating areas of China and caused severe damage to rice production.  Cnaphalocrocis medinalis granulovirus (CnmeGV), a naturally occurring baculovirus, is revealed as a potential microbial agent for the pest control.  Field applications of CnmeGV were conducted against rice leaffolder larvae in rice paddies.  CnmeGV infected the larvae not only in the current generation but also in the successive generation, resulting in a sustained infection in the larva population for at least 48 days.  Under diferent concentrations of CnmeGV (7.5×10¹¹ and 1.125×10¹² occlusion body (OB) ha^–1) at 30 days after spraying, larval population reduced up to 76.32% and rice leaf rolled rate kept in 15.42%.  Simultaneously, CnmeGV had no impact on arthropod predators of C. medinalis, with abundances ranging from 2.39 to 3.79 per ten hills.  These results revealed that CnmeGV is suitable as a bio-pesticide for rice leaffolder management in rice paddies.