Effect of Wild and Laboratory-reared Female Gypsy Moths, Lymantria dispar L. (Lepidoptera: Lymantriidae), on the Capture of Males in Pheromone-baited Traps

Abstract

Laboratory-reared male gypsy moths ( Lymantria dispar ) were released daily at the center of two 400-by-400-m grids of pheromone traps in a pine and a hardwood site before, during, and after the natural occurrence of wild adult females. There was no obvious diminution in recaptures of released males when wild females were present. However, in a second test, laboratory-reared females were placed at the center of one of the two grids. There was a significantly smaller proportion of males recaptured in the hardwood site when laboratory-reared females were present than when they were absent. In a third test, there was no difference in the proportion of mated versus unmated laboratory-reared males recaptured after release at the center of a grid without females. There were positive correlations between the proportion of males recaptured and ambient temperature and between the daily proportions recaptured in the two grids. There was a marked difference between the two sites in the wild adult sex ratio.