GENOTYPIC VARIATION AMONG WILD ISOLATES OF DOUGLAS-FIR TUSSOCK MOTH (LEPIDOPTERA, LYMANTRIIDAE) NUCLEAR POLYHEDROSIS-VIRUS

Larvae of the Douglas-fir tussock moth, Orgyia pseudotsugata (McDunnou gh), were reared from egg masses collected at 10 locations in 6 geogra phic regions of British Columbia. DNA of O. pseudotsugata nuclear poly hedrosis virus (OpMNPV) extracted from these larvae and from commercia l OpMNPV viral-insecticide preparations (Virtuss and TM-BioControl-1) were subjected to restriction endonuclease (REN) analysis with PstI an d SalI. Southern blot analyses of the REN cleavage products revealed p olymorphisms in 54.5% of samples digested with PstI and 43.3% of sampl es digested with SalI. Five PstI genotypes and 2 SalI genotypes were d etected. Each of the five PstI REN patterns demonstrated either one or the other of the SalI REN patterns, creating 10 possible combined gen otypes, 8 of which were actually detected. Rare and common genotypes w ere mapped to each of the 6 geographic regions.