Nuclear polyhedrosis virus infection ofPseudoplusia includens [Lep.: Noctuidae] larvae: Effect on post larval stages and transmission

Abstract

Treatment ofPseudoplusia includens (Walker) larvae in either the 4th, 5th or 6th stage with a nuclear polyhedrosis virus (NPV) did not affect the weight or sex ratio of surviving pupae. Pupal mortality was low but increased with the dosage of the NPV larvae had received. Also, mortality of pupae from larvae treated in the 5th or 6th stage was higher than from larvae treated in the 4th stage. Adult longevity was not affected by the virus. Fecundity and egg viability were reduced following most treatments of 6th stage larvae but not 4th or 5th stage larvae. Adults exposed to NPV at 3 dosages during the 6th larval stage were released in cages on soybean. Some of the progeny succumbed to NPV infection. Progeny mortality increased over a 7 week period of adult release, but did not differ significantly between treated and untreated groups by the end of the 7 week period.