Estimates about which scale insect species are most frequently encountered in U.S. landscapes and commercial production systems are largely anecdotal. This survey of records maintained across about 15 years within the National Plant Diagnostic Network (NPDN) National Data Repository (NDR) returned information from 10,671 records of 192 scale insect species and 23 suspected species that were associated with ornamental plants. This broad species diversity challenges our ability to effectively train diagnosticians, can confound species identification accuracy, and impedes outreach efforts and resource development. To help focus future efforts in the development of outreach resources and diagnostic training guides, lists were assembled that identified the 60 top-ranked soft, armored, mealybug, and other scale insect taxa most frequently diagnosed within NDR records. Diagnostic service records from Georgia, North Carolina, South Carolina, and Tennessee provided more extensive information regarding sites or client types from which submitted samples originated. Results are being used to develop web-based, image-rich guides to key scale insect taxa in the southeastern United States that will explain life cycles, behaviors, and biology for pest species. These web-based guides can be exploited to optimize pest management actions.