DISRUPTION OF PHEROMONE COMMUNICATION OF THE RUSTY TUSSOCK MOTH, ORGYIA ANTIQUA (LEPIDOPTERA: LYMANTRIIDAE), WITH (Z)-6-HENEICOSEN-11-ONE

Abstract

Tussock moths of the family Lymantriidae are an important group of forest defoliators that characteristically have periodic outbreaks. The sex pheromone of the female Douglas-fir tussock moth, Orgyia pseudotsugata (McDunnough), has been identified as (Z)-6-heneicosen-11-one (Smith et al. 1975) and shown to be sexually stimulating to males of seven tussock moth species in two genera, Orgyia and Dasychira (Daterman et al. 1976; Grant 1977). Laboratory tests demonstrated that this compound could disrupt mating of both the whitemarked tussock moth,O. leucostigma (J.E. Smith), and rusty tussock moth, O. antiqua (L.), when the adults were maintained in an atmosphere containing the chemical (Grant and Frech 1976). Subsequently field tests in small plots treated with the same material released into the atmosphere at a rate equivalent to 20-50 mg/ha/day demonstrated that pheromone communication of whitemarked tussock moths and a conifer-feeding tussock moth, Dasychira plagiata (Walker), could be disrupted in their natural habitat (Grant 1978). Similar disruption was obtained with field populations of the Douglas-fir tussock moth (Sower and Daterman 1977). The present report describes the disruptive effects of (Z)-6-heneicosen-11-one in the field on the pheromone communication of another species, the rusty tussock moth.