An evaluation of the impact of sublethal dosages of nuclear polyhedrosis virus in larvae on pupae, adults, and adult progeny of the fall armyworm, Spodoptera frugiperda

Abstract

Spodoptera frugiperda nuclear polyhedrosis virus (NPV) was bioassayed against 2-day-old S. frugiperda larvae by feeding them meridic diet which was surface-contaminated with known quantities of NPV. The LC 50 and LC 75 were determined to be 87 and 142 polyhedral inclusion bodies/mm 2 of diet surface, respectively. The same inoculation method, using these two dosages and 2-day-old larvae, was used in subsequent experiments to obtain pupae which survived each dosage. Surviving pupae were sexedm weighed, and allowed to eclose. Adults obtained were allowed to mate. No significant differences were found in sex ratio, pupal weight, adult emergence, total egg production, oviposition rate, and egg viability between treated insects and healthy controls, regardless of NPV dose.