The stage specific mortality of larvae of Pseudoplusia includens [Chrysodeixis includens] was determined following treatment with Pseudoplusia [Chrysodeixis] nuclear polyhedrosis virus to soyabeans in the field in Arkansas at various dosages. Overall mortality due to the virus was highest (33.1%) at the highest treatment rate (168 larval equivalents per ha, where 1 larval equivalent (LE) = 6 X 109 PIB) and was dependent on the larval development stage. Larvae estimated to be at the 2nd stage of development were the most susceptible (68%). Parasitism, primarily by species of Apanteles and Copidosoma, caused about 42% mortality and was relatively uniform across all virus treatments. none