Systematics Of The Oriental Tribe Sinosenini And Its Allies (Hemiptera: Cicadoidea) With Special Reference To The Phylogenetic Status Of The Sinosenini

There are two families in Cicadoidea (Hemiptera: Auchenorrhyncha), Tettigarctidae and Cicadidae. The higher classifications have been traditionally based on structures associated with the production of sound and related morphological structures, viz. timbals, timbal covers, tympana, and wing and genital stridulation mechanisms. However, the phylogenetic status of some groups, e.g., cicadas of the tribe Sinosenini (comprise only one genus Karenia restricted confined to the Southwest China and Burma) having neither timbals nor supplementary stridulatory mechanisms remained questionable.This study obtains the sequences of 23 species in the three subfamilies, based on three mitochondrial genes (cytochrome oxidase subunits I, cytochrome b and 16S rDNA). Subpsaltria yangi, belonging to the subfamliy Tettigadinae, is regareded as the outgroup. The aligned sequences are executed in Mega4.0 to calculate variable sites, conserved sites, parsimony-informative sites and the average content of A, T ,C, G; the pairwise diatance obtains by using Kimura’s 2-parameter model (K2-P). Maximum parsimony, maximum likelihood and Bayesian analyses are chosen to construct the phylogeny based on the single gene 16S rDNA, the combined genes 16S rDNA + Cyt b, 16S rDNA + COI and 16S rDNA + Cyt b + COI, respectively. The results are as follows:1. The average content of A+T is much higher than the content of C+G; this strong A+T bias in nucleotide frequencies is similar to that of other insects. The analysis in Mega 4.0 based on Kimura’s 2-parameter model (K2-P) obtain the pairwise distances, the average pairwise divergence are lower than 25.0%~30.0%. Chi-square test of homogeneity of base frequencies across taxa indicate there is no significant nucleotide bias among taxa (16S rDNA chi-square =15.054, d.f. = 66, P = 1.000; 16S rDNA + Cyt b chi-square =18.733, d.f. = 57, P = 1.000; 16S rDNA + COI chi-square =19.498, d.f. =57, P = 1.000; 16S rDNA + Cyt b + COI chi-square =28.862, d.f. =57, P =0.999).2. The MP, ML and BI trees based respectively on 16S rDNA, 16S rDNA + Cyt b, 16S rDNA + COI and 16S rDNA + Cyt b + COI reconstruct the relationship of the group in the Cicadidae.(1) ((Karenia + Macrosemia) + Meimuna) form a clade, and Karenia is transferred from the Cicadettinae to the Cicadinae. The tribe Sinosenini (only contain one genera, Karenia) is synonymized with Cicadini, a new subtribe Sinosenina is placed in Cicadini.(2) Five genera (Pomponia, Meimuna, Macrosemia, Hyalessa and Tanna) in the tribe Cicadini are not in a clade, therefore the tribe Cicadini is not a monophyletic group.(3) The Mogannia (in the Cicadinae) is placed in the clade of the subfamily Cicadettinae, therefore the subfamily Cicadinae is not monophyletic. The tribe Cicadatrini is therefore transferred from the Cicadinae to the Cicadettinae.(4) The genera Graptopsaltria and Angamiana form a clade, as supports the conclusion of Hayashi (1978) that Polyneurini includes Graptosaltria, Formotosana, Polyneura and Angamiana.3. The higher classification based mainly on characters of sound organs and related morphological structures (timbals, timbal covers, tympana, and wing and genital stridulation mechanisms) needs urgent revised.