Potential invasive species of scale insects for the USA and Caribbean Basin.

percentage of the total number of species repre­ sented in the USA and the respective zoogeo­ graphic regions indicated beside the number of species (Table 18.1). These data were extracted from ScaleNet (2011), an online database that includes all published information on scale insect species. A few subspecies might be included as part of the total number of species; in addition, the creators of ScaleNet place the northern part of Mexico in the NA, whereas southern Mexico is in the NT region. Northern mainland China is included in the PA, whereas southern China is in the OR region. This differs from the interception data presented herein, in that all of Mexico is included in the NT region; all of mainland China, Japan and Korea are placed in the Eastern PA region; and the records from the AU region are separated into those from Australia and those from the PI. All scale insects are obligate plant feeders, and therefore are almost always found closely associated with plants, commonly being inter­ cepted on imported plant material. In its native area, an ecological balance usually exists between the population of the scale insect and its natural enemies, which maintains the population of the scale insect below economic injury levels. However, when a species is separated from its nat­ ural enemies, primarily due to human mediation