Effects of the Fall Armyworm (Lepidoptera: Noctuidae) on Rice Yields

Abstract

Effects of fall armyworm, Spodoptera frugiperda (J. E. Smith), feeding on rice, Oryza sativa L., were studied in the field during 1983 and 1984. Increased S. frugiperda infestation levels resulted in increased rice defoliation, reduced plant and panicle density, and reduced rice yields. Yield component studies indicated that lower yields on infested plots were the result of reduced plant stand and panicle density. Kernel weight and percent filled kernels were not affected. Yield reductions were linearly related to S. frugiperda larval density. The linear model [E(y) = bx1] accounted for a large proportion of the variance of yield reduction during both years.