Genotypic Variation Among Wild Isolates of Douglas-Fir Tussock Moth (Lepidoptera: Lyntantriidae) Nuclear Polyhedrosis Virus

Abstract

Larvae of the Douglas-fir tussock moth, Orgyia pseudotsugata (McDunnough), were reared from egg masses collected at 10 locations in 6 geographic regions of British Columbia. DNA of O. pseudotsugata nuclear polyhedrosis virus (OpMNPV) extracted from these larvae and from commercial OpMNPV viral-insecticide preparations (Virtuss, and TMBioControl-1) were subjected to restriction endonuclease (REN) analysis with Pst I and SaI I. Southern blot analyses of the REN cleavage products revealed polymorphisms in 54.5% of samples digested with PstI and 43.3% of samples digested with SaII. Five PstI genotypes and 2 SalI genotypes were detected. Each of the five Pst/I REN patterns demonstrated either one or the other of the SalI REN patterns, creating 10 possible combined genotypes, 8 of which were actually detected. Hare and common genotypes were mapped to each of the 6 geographic regions.