The lackey moth, Malacosoma neustria (Linnaeus, 1758), a worldwide pest, causes extensive economic losses on particularly hazelnut, Prunus, Quercus, Populus, and Salix trees. In this study, a local nucleopolyhedrovirus (NPV) was isolated from the-larvae of M. neustria in the northeast of Turkey. It was named ManeNPV-T2. Electron microscopic observations showed that the polyhedra of the new isolate contain several virions with multiple nucleocapsids packaged within a single viral envelope. Restriction endonuclease analysis of ManeNPV-T2 DNA indicated that it has a different restriction profile compared to the previous Turkish and Latvian isolates. The phylogenetic analysis of the amplified polh sequence of ManeNPV-T2 showed its relation to the other NPVs from Malacosorna species. Mortality values for third instar M. neustria larvae ranged from 48% to 100% according to the concentration of polyhedral occlusion bodies. Based on screening tests, the LD50 value of the new isolate was calculated as 1.34 x 10(4) occlusion bodies per larvae. Consequently, ManeNPV appears to be a promising microbial control agent for biocontrol of M. neustria.