DNA barcoding of Deltocephalus Burmeister leafhoppers (Cicadellidae, Deltocephalinae, Deltocephalini) in China

We investigated the feasibility of using the DNA barcode region in identifying Deltocephalus from China. Sequences of the barcode region of the mitochondrial COI gene were obtained for 98 specimens (Deltocephalus vulgaris – 88, Deltocephalus pulicaris – 5, Deltocephalus uncinatus – 5). The average genetic distances among morphological and geographical groups of D. vulgaris ranged from 0.9% to 6.3% and among the three species of Deltocephalus ranged from 16.4% to 21.9% without overlap, which effectively reveals the existence of a “DNA barcoding gap”. It is important to assess the status of these morphological variants and explore the genetic variation among Chinese populations of D. vulgaris because the status of this species has led to taxonomic confusion because specimens representing two distinct morphological variants based on the form of the aedeagus are often encountered at a single locality. Forty-five haplotypes (D. vulgaris – 36, D. pulicaris – 5, D. uncinatus – 4) were defined to perform the phylogenetic analyses; they revealed no distinct lineages corresponding either to the two morphotypes of D. vulgaris or to geographical populations. Thus, there is no evidence that these variants represent genetically distinct species.