Systematic Study On The Subfamily Cicadellinae(Hemiptera:Cicadellidae)

Cicadellinae is one of the largest groups of Cicadellidae and distribute worldwide and its phylogeny and classification system need to be revised.In this study,fourteen species from eight closely related subfamilies were used as outgroup,and 243 species were selected worldwide as ingroup,combining 147 adult morphological characters with DNA sequence data from nuclear 28 S r DNA D8,histone H3 genes,and mitochondrial 16 S r DNA,COI,and COII.Phylogeny of the family was reconstructed based on morphological characters and molecular data separately,and integrating both morphological and molecular data together.Both maximum-likelihood and Bayesian were used to analysis the tree topologies that indicated the monophyly of Cicadellinae,confirmed the monophyly of Proconiini,Phereurhini and Oncometopiini respectively.The largest tribe Cicadellini was polyphyletic and the result strongly supported to divide it into two groups,Cicadellini and a new tribe Bothrogoniini trib.nov.The phylogenetic analysis of the group elucidated the relationships of the tribes and genera,and provided a solid basis for revising the Cicadellinae classification system.Moreover,we also studied the biogeography of the subfamily Cicadellidae used Bayesian relaxed clock method with seven fossils to estimate the divergence time.The result integrating with reconstruction of ancestral area recovered that Cicadellinae originated in Gondwana during Cretaceous;the deepest divergences coincided with breakup of Gondwana;the divergence of Neotropical and Nearctic Cicadellinae was closely related to the fragmentation and connection of North American and South American;the presence of Gondwanan lineages in tropical Asia was significantly correlated with out-of-India colonization;the biogeographical history of oriental Cicadellinae colonization involves long-distance dispersal(LDD).Meanwhile,we also explored the relative driving factor of colonization event.The study of current specific distribution patterns of Cicadellinae recovered the greatest diversity in Neotropical region with 228 genera,68%;while Australian 4 genera,1%;Afrotropical 6 genera,2%;Palearctic 6 genera,2%,being depauperate with much lower species diversity,which is closely related with the factors and events,such as plate tectonic and continental drifting,climate changes,and host plant.Based on the phylogeny reconstruction,we proposed here that Cicadellinae comprises 5tribes including 337 genera and around 3100 known species worldwide.The world check-list of genera and species of Cicadellinae was revised;and 140 species out of 5 tribes and 111 genera were described and illustrated,including a new tribe,Bothrogoniini trib.nov.,and 7new species(Catenocola longus,Diestostemma longissimus,Dilobopterus signum,Dilobopterus brachium,Emadiana finitimus,Sochinsogonia multimacula,Sochinsogonia radicalia).