Benefits of imidacloprid, a systemic neonicotinoid insecticide, have been offset by reports of secondary mite outbreaks on treated plants. Earlier studies established negative effects of imidacloprid on a few keystone predators and suggested that reductions in natural enemy abundance or activity could explain increased mite populations on treated plants. In this study, we focused on determining if two neonicotinoids affect key predators of mites and the community of natural enemies in general. The impact of imidacloprid and acetamiprid on beneficial insect populations was studied using boxwoods, boxwood spider mites (Eurytetranychus buxi), and associated natural enemies in a landscape setting in College Park, MD in 2005. The effect of imidacloprid on natural enemies was examined using American elms, Tetranychus schoeni, and associated natural enemies in Central Park, New York in 2004, 2005, and 2006. Foliage samples and passive sticky traps were utilized to assess beneficial arthropod populations. The key predators of mites in both systems were identified and enumerated. Populations of several natural enemies were higher on treated plants compared to untreated ones. This appears to be a numerical response to far greater abundances of spider mite prey observed after applications of neonicotinoids. Our findings do not strongly support the notion that disruptions of natural enemy activities are responsible for outbreaks of spider mites in landscapes following the application of neonicotinoids.