During 1979 and 1981, populations of ground-dwelling predators and parasites in research and commercial cabbage fields in upstate New York were assessed by pitfall trapping to determine species composition, abundance, phenology, and the impact of insecticides on them. Staphylinidae, Phalangida, Carabidae, and Araneida were consistently the most abundant predaceous taxa. Carabids and Staphylinids together comprised 75.9 and 74.1% of all predaceous or parasitic insects in commercial fields during 1979 and 1981, respectively. One of the 32 species of Carabidae captured,Pterostichus melanarius(Illiger), accounted for>50% of the total number of Carabidae. Total number of predators and parasites tended to decline from July through September in both treated and untreated fields, but this decline was hastened by the use of broad-spectrum insecticides.