Mating Disruption of Gypsy Moth (Lepidoptera: Lymantriidae) Following Ground Application of High Rates of Racemic Disparlure

Abstract

Field studies were conducted in sparsely infested 4-ha plots in West Virginia between 1988 and 1990 to evaluate the effectiveness of high rates of racemic disparlure in reducing male trap catch and female mating, and suppressing populations of gypsy moth, Lymantria dispar (L.). Five-m grids of manually applied Luretape containing 700 g (AI)/ha (release rate of 222 g/ha/yr; 400 release points per ha) significantly reduced the number of male moths captured in (+)-disparlure-baited traps and disrupted mating for two consecutive seasons. In both years, reduction in male trap catch was considerably greater than reduction in female mating success. Data collected in situ from female insects in 1989 showed mating was reduced 12% in Luretape plots. Also in 1989, mating success among caged females was significantly greater in the upper canopy of Luretape-treated plots than at ground level. Intensive egg-mass surveys (50 0.01-ha plots per central 1-ha site) showed that gypsy moth populations increased at similar levels in Luretape and control woodlots over a 3-yr period.