LAUSR

Abstract Biochar application to soils can alter soil nutrient dynamics and thus change the uptake of nutrients by plants. The effect of such changes on leaf-chewing caterpillars remains unknown. In this study, we examined the effect of biochar amendment at varying rates on the developmental and reproductive performances of the rice leaf-folder Cnaphalocrocis medinalis on potted rice, and investigated C. medinalis population size over two years in a paddy field applied with biochar. We found that biochar amendment prolonged larval development, increased larval mortality, decreased mature larval body weight, lowered consumption of rice leaves, and reduced adult longevity of C. medinalis. We did not detect a difference in fecundity of the females that survived to adulthood among biochar treatment levels. The two-year paddy field experiment showed a reduced C. medinalis population as a consequence of biochar application in the first year, and a population similar to the control in the next year. The results from the current research suggest that biochar can impair C. medinalis development and may have a negative consequence on its populations.