Abstract
Using morphological assessments and phylogenetic inference, we described a new subterranean termite species in the genus Reticulitermes in southern California: Reticulitermes rusti sp. nov. Genetic analyses utilizing 3 mitochondrial loci (16S rRNA, COI, and COII) and 7 microsatellites successfully distinguished the new species from 2 other Reticulitermes found in southern California: R. hesperus Banks and R. tibialis Banks. Empirical measurements of key morphological characters further support the delineation of R. rusti as a new species. While R. rusti is genetically closer to R. tibialis, its soldier caste is morphologically similar to that of R. hesperus. We recommend confirming species identification by sequencing the COI or COII region. The integration of biological, genetic, and morphological data robustly supports the recognition of R. rusti as a distinct new species in southern California.