Phylogenetic Study Of Evacanthinae (Hemiptera:Cicadellidae)

Evacanthinae is distributed worldwide in all the six zoogeographical regions but mainly in the Oriental Region.Its classification was unstable over the past decades.Previous phylogenetic analyses supported the monophyly of Evacanthinae including tribes Balbillini,Evacanthini,Nirvanini and Pagaroniini,but were not completely convincing and did not include sufficient taxon samples of various tribes and genera to resolve relationships among them.In this study,phylogenetic relationships among major lineages of the Evacanthinae were explored by analysing a dataset of 100 discrete morphological characters and DNA sequence data from nuclear genes 28 S rDNA(28S),Wingless(WG)and Histone H3(H3)and the mitochondrial gene cytochrome c oxidase I(COI).Seventy-seven taxa representing all evacanthine tribes and all regional faunas,and fourteen putative outgroup taxa were included.Maximum-likelihood and Bayesian analyses yielded similar tree topologies that were well resolved with strong support for the monophyly of Evacanthinae and its four previously included tribes,and supported to establish a new tribe Pentoffiini trib.nov.,but indicated that Draconirvana Dietrich,was improperly placed to tribe Nirvanini and that Sophonia Walker,Evacanthus Le Peletier & Serville,Bundera Distant,Paraonukia Ishihara and Onukia Matsumura are polyphyletic groups.Divergence times for recovered nodes were estimated using a Bayesian relaxed clock method with two fossil calibration points.The results suggest that the deepest divergences,corresponding to the origins of tribes,coincided with breakup of Gondwana but that more recent divergences(among genera)occurred largely within a single biogeographic realm during the Paleogene,with a few long-distance dispersal events occurring between the Oriental and Afrotropical Regions and in both directions around the northern border of the Pacific Rim.Biogeographical analyses suggest that Evacanthinae originated in Neotropical region,Evacanthini originated in Indochina Peninsula,Nirvanini appears to have originated in the Neotropics and later dispersed into the Oriental Region and Africa.This study clarified the relationship between Nirvaninae and Evacanthinae as well as other related groups,supported the treatment of Nirvaninae as a junior synonym of Evacanthinae,and revised the system of Evacanthinae.The study also provided useful information for the phylogenetic research of Cicadellidae.Integrative taxonomy is applied to distinguish very closely related and cryptic species.In order to infer the boundaries of seven species(or units)of the evacanthine leafhopper genus Bundera Distant(Hemiptera: Cicadellidae),an integrated analysis based on morphology,mitochondrial DNA and hyperspectral reflectance profiling was conducted.The species-specific divergence of five morphologically similar species(B.pellucida,B.sp.1,B.sp.2,B.sp.3 andB.sp.4)was revealed in mitochondrial DNA data and reflectance profiling.A key to identifying males is provided,and their morphological characters are described.Despite their morphological similarities,the genetic distances of thecytochrome c oxidase subunit I(COI)gene among the tested species are relatively large(5.8–17.3%).Average reflectance profiles(37 spectral bands from 411-870 nm)from the dorsal side of specimens were classified based on linear discriminant analysis.Cross-validation of reflectance-based classification revealed that the seven species could be distinguished with 91.3% classification accuracy.This study verified the feasibility of using hyperspectral imaging data in insect classification,and our work provides a good example of using integrative taxonomy in studies of closely related and cryptic species.So far,Evacanthinae comprises about 70 genera 500 described species in 5 tribes worldwide.Supplemented to previous research,Evacanthinae are reviewed worldwide,new taxa are described and the world check-list of genera and species of Evacanthinae is attached in this dissertation.Totally,39 species of 23 genera of in Evacanthinae are describedand illustrated here,including1 new tribe,6 new genera,30 new species,7 new combinations and 2 new synonyms(1 new tribe,4 new genera,10 new species and 5 new combinations have been published).