Effect of Synthetic Pheromone on Gypsy Moth (Lepidoptera: Lymantriidae) Trap Catch and Mating Success Beyond Treated Areas

Abstract

Racemic disparlure sprayed at doses of 37 to 75 g/ha (AI) for mating disruption of gypsy moths, Lymantria dispar (L.), interfered with male moth search behavior outside of treated plots. Counts of feral male moths in pheromone-baited traps and the number of recaptured laboratory-reared moths gradually increased with increasing distance from treated areas. In most cases this effect was observed up to 250 m from treated plots. However, in one location it extended to 600 m along a narrow valley. The proportion of tethered females that mated during 1-d exposure increased gradually with increasing distance from treated plots. The relationship between male moth capture rates in pheromone traps and mating success of tethered females near treated plots was the same as the one observed in previous studies in pheromone-free areas.