In 1987, four gypsy moth,Lymantria dispar, (L.) densities were established in eight 1-ha plots in western Massachusetts, ranging from 50,000 to 1.4 M neonates per hectare. Two tachinid parasitoid species,Compsilura concinnata(Meigen) andParasetigena silvestris(Robineau-Desvoidy), exhibited spatial density-dependent parasistism andC. concinnatawas the major source of gypsy moth mortality. This study investigated whether spatial density-dependent mortality in 1987 translated into temporal density-dependent mortality of experimental gypsy moth populations created the following year (1988).C. concinnatawas responsible for the largest percentage of gypsy moth mortality again in 1988, however, overall mortality caused byC. concinnatain 1988 was considerably less than in 1987. Gypsy moth mortality caused byP. silvestriswas greater in 1988. The killing power of either parasitoid in 1988 were not linearly related to the estimated density of the parasitoids produced in the previous year. We saw no evidence for a between-generation numerical response (1-ha scale) of either the generalist parasitoid,C. concinnata, or the specialist parasitoid,P. silvestris, between 1987 and 1988.