Experimental forest releases of calosoma sycophanta (Coleoptera : Carabidae) against the gypsy moth

Releases of limited numbers of Calosoma sycophanta L. adults into high populations of gypsy moths, Lymantria dispar L., were made in 1988 and 1989. In 1988 0-40 wing-clipped beetle adults were released into four plots. Larval survival of gypsy moths was least in plots receiving the most beetles, but based on gypsy moth pupal mortality and numbers of immature beetles seen, adults did not reproduce. In 1989, a release with four replicates was conducted in which 0 beetles, 20 intact beetles, or 20 beetles with clipped wings were released into separate plots. Larval survival rates for gypsy moths could not be adequately assessed, because of overwhelming mortality due to an Entomophaga fungus, but there were significantly more beetle larvae in plots receiving intact beetles than in the other treatments, and pupal mortality occurred earlier and was greater in release plots than in check plots. The releases show that a small number of adult beetles, through progeny production, can have an effect on gypsy moth populations.