Comparative Effectiveness of Lymantria Nuclear Polyhedrosis and Cytoplasmic Polyhedrosis Viruses Against the Gypsy Moth (Lepidoptera: Lymantriidae)

Abstract

Gypsy moth, Lymantria dispar (L.), larvae were susceptible to both a Connecticut isolate of nuclear polyhedrosis virus (NPV) and a Korean isolate of cytoplasmic polyhedrosis virus (CPV). The NPV was considerably more virulent (LC50 = 18,115 polyhedral inclusion bodies [PIB] per ml) than the CPV (LC50 = 95,489 PIB per ml). Larvae infected with NPV also died more quickly than those infected with CPV. Larval weight was affected differently by the two viruses. In the case of NPV, larval weight among survivors at d 7 was not affected adversely until virus-caused mortality exceeded 70%. For CPV, larval weight was affected adversely before mortality caused by the virus had occurred.