Some orchard insect pests are regulated at low densities in feral habitats by natural enemies, but often persist at high densities in commercial apple orchards because insecticides decimate natural enemies and/or commercial orchards provide a rich and abundant resource for herbivores. Commercial orchard because of their lack of plant diversity may be less than optimal habitats for many natural enemies. Recent experiments conducted in NY indicated that orchards are quite adequate habitats for the natural enemies of native North American lepidopteran leafrollers. To determine the potential for enhancing biological control of the Obliquebanded leafroller (OBLR) manipulating insecticide use, we conducted studies to assess parasitism and predation of OBLR in orchards treated with conventional insecticides and with newer, more selective compounds. To eliminate the potentially lethal effects of insecticides and to insure that uniform host populations were available to monitor parasitism, trees were artificially infested with sentinel larvae from laboratory colonies. Larvae were exposed to natural enemies for 48 hours, recollected, and reared in the laboratory on diet. Emerging parasitoids were identified. Appropriate statistical methods were used to compare natural enemy levels and species diversity in the two insecticide regimes. Both treatment and landscape affected the levels and species diversity of natural enemies. Actia interrupta (Tachinidae), Oncophanes americanus (Braconidae) and Exochus albifrons (Ichneumonidae) were identified as the most important parasitoids. Predacious insect species under each treatment were also identified using different collecting methods.