For each species in which this comparison was possible (n = 73), maximum intraspecific variation is compared to minimum interspecific congeneric difference. For illustration purposes shown here, 2.0% is chosen as a cutoff between usual values for intra- and interspecific variation. This divides the graph into four quadrants that represent different categories of species: (I) Intraspecific distance, <2%; interspecific distance, >2%: concordant with current taxonomy; (II) Intraspecific distance, >2%; interspecific distance, >2%: probable composite species (i.e., candidate for taxonomic split); (III) Intraspecific distance, <2%; interspecific distance, <2%: recent divergence, hybridization, or synonymy; (IV) Intraspecific distance, >2%; interspecific distance, <2%: probable misidentification of specimen.