Phylogeography Of The Cicada Genus Karenia Distant (Hemiptera: Cicadidae)

Previous studies on Karenia were mainly focused on morphological taxonomy, butinformations for its molecular identification, phylogeny and biogeography remain unavailable.Moreover, Karenia caelatata Distant which has a wide distribution, shows remarkablephenotypic variations, and has confounded the delimitation of this species morphologically.In the present study, we analyzed the morphological variations of K. caelatata based onexternal morphology and geographical distribution from previous studies. Individualmorphological variants were selected for molecular identification based on mitochondrial COI,COII and Cytb, and the composition of sequences were analyzed. Phylogenetic analyses,containing all unique haplotypes, were conducted using maximum-likelihood (ML) andBayesian inference (BI) optimality criteria (K. chama Wei&Zhang,2009was selected as theoutgroup). The results are as follows:1. The genus Karenia mainly distribute in southwestern China (Yunnan Province oradjacent areas), Vietnam and Burma, and has a low level of diversity; except that K. caelatatais dispersed to northern regions, the remaining four species have a narrower range.2. The phylogenetic results indicate that the congruence between the morphologicalvariations and genetic divergence is quite low, with seemingly distinct morphological variantsshowing limited genetic divergence.3. ML and BI trees have a high consistency only based on the combined gene COI+COII+Cyt b according to comparative analysis. All phylogenetic trees show that all variantsof K. caelatata belong to a monophyletic group with high support value. The populations ofHunan Province and Sichuan Province have remote phylogenetic relationships to otherpopulations of K. caelatata and generate independent clades, respectively; the population ofHubei Province forms a sister group to populations in Shaanxi, Shanxi and Henan Provinces;the populations of Shaanxi Province and Shanxi Province gather into one clade, and form asister group to the populations in Henan Province.4. The data on phylogeny and biogeography show that the southwestern China and/oradjacent areas are distribution center of the genus Karenia. Southwestern China and/or adjacent areas could have been the refuges for Karenia during the Quaternary glaciation; andsome species of Karenia then spread northward upon the postglacial period along with themountain ecosystems.5. Yizhang County of Hunan Province is recorded as a new range extention for K. chama.Yizhang County is far apart to Shangri La County of Yunnan Province (known distribution)which suggests that K. chama has a much wider geographic range than we previously knew.