Armored scale insects (Hemiptera: Diaspididae) are plant-feeding insects with species that have an unusually high host range. One particular host genus (Ceanothus) has multiple species found throughout the chapparal of the coastal mountain ranges in central California and Baja California. Currently, 28 species of armored scale are recorded as associates of Ceanothus, but it is unknown what the disparity and diversity in attack rate is amongst these species. These data are necessary to understand the ecological dynamics in this host-plant association. Here, I present the results of large-scale sampling of Ceanothus found throughout San Diego County, California. Genetic analyses were used to confirm species identifications and to provide insights into the genetic diversity and population structure of these species. Conclusions drawn from this analysis provide insight into taxonomic diversity, population structure for these generalist insects, and dispersal maps for native and invasive armored scales. A phylogenetic analysis has provided more evidence that a previously described species (Hemiberlesia lataniae) may be a cryptic species complex native to western North America.
