An integrated management system for the Douglas-fir tussock moth in southern British Columbia

Abstract

An integrated, long-term system to detect and treat infestations of Douglas-fir tussock moth in the Southern Interior of British Columbia was successfully implemented between 1984 and 1999. All aspects of recent research were implemented during an integrated control program conducted between 1991 and 1993. Many localized, incipient outbreak populations of tussock moth were detected prior to significant defoliation and treatments of a nuclear polyhedrosis virus (NPV) were applied. The application of NPV to sites with increasing tussock moth populations effectively terminated the localized infestations. The combination of early detection and application of NPV greatly reduced damage when compared to previous tussock moth outbreaks. Other program components were evaluated during the outbreak including: 6-trap cluster pheromone monitoring sites and singlet pheromone monitoring sites that correctly predicted outbreak level tussock moth populations; comparison between stored and new virus; comparison between virus formulations (Virtuss® versus TM Biocontrol-1®); evaluation of alternate swath versus entire coverage application of virus; and reduced dosages of virus. All virus trials were effective in reducing tussock moth populations to pre-outbreak levels. Future research and applications of the methodology are discussed.