The objective of this report is to describe the current increase in Douglas-fir tussock moth (Orgyia pseudotsugata McDunnough) activity in northern Idaho and Montana. The report also relates current conditions to historical and future trends and larger scale increasing tussock moth activity in surrounding western states.
In conjunction with a proposed suppression project against the Douglas-fir tussock moth in northern Idaho, more than 1,000 larvae were collected from sample plots throughout the 32,000-acre treatment area. We had hoped to determine naturally occurring mortality factors which may have contributed to lower than anticipated population levels. Reared on...
The genome of the multicapsid nuclear polyhedrosis virus of
Orgyia pseudotsugata (OpMNPV) was mapped by examining overlapping
Hindlll fragments from cosmid clones which had been constructed
from partial Hindlll digests of viral DNA. Five OpMNPV cosmid
clones containing fragments encompassing the entire OpMNPV genome
were hybridized to blots of DNA...
Loss of early instar Douglas-fir tussock moth (Orgyia pseudotsugata McDunnough) (DFTM) has been found to constitute 66-92% of intra-generation mortality and to be a key factor in inter-generation population change. This death has been attributed to dispersal and to arthropod predation, two factors previously judged more important to an endemic...