Lymantria mathura nucleopolyhedrovirus: Identification, occurrence and genetic diversity in Iwate Prefecture, Japan.

•NPV disease was observed in outbreak populations of Lymantria mathura and L. dispar.•Lymantria mathura nucleopolyhedrovirus (LymaNPV) was newly designated.•Nuclear polyhedrosis in L. mathura was exclusively caused by LymaNPV.•A small fraction of nuclear polyhedrosis in L. dispar was due to LymaNPV.•Variants of LymaNPV did not randomly distribute among L. mathura populations.