Phylogeny And Taxonomy Of The World Panorpidae(Mecoptera)

Panorpidae is the largest family in the order Mecoptera(Insecta:Holometabola),with approximately 500 known species currently assigned into one extinct and eight extant genera.Up to date,the phylogeny of Panorpidae is unsatisfactorily resolved.The family is considered to split basally into two subfamilial status-meriting clades;and the largest two genera in Panorpidae,Panorpa and Neopanorpa,are both confirmed to be paraphyletic groups and may need further splitting.Previous taxonomic studies of Panorpidae mainly focused on local regions,and the relationships among different faunas remain largely unclear to date.Due to historical reasons and methodological restrictions,many species lack detailed descriptions and illustrations,impeding further studies in other aspects,such as species identification.Therefore,phylogenetic analysis is urgently needed for Panorpidae by combining morphological characters and DNA sequence data to further decipher the faunal relationships and evolutionary history.Meanwhile,a comprehensive taxonomic revision is also urgently needed at the global scale to provide a solid foundation for the identification of species.In Chapter I,the general knowledge is reviewed for Panorpidae in the context of its systematic position,biology,phylogenetics,and taxonomy,etc,with existing problems introduced in detail for the phylogenetic and taxonomic studies.In Chapter ?,morphology of Panorpidae is investigated for the external structures and internal organs of adults,and external structures of the immature stages,with terminology standardized,providing a foundation for further phylogenetic analysis and taxonomic studies.In Chapter ?,phylogenetic analyses were conducted with two species in two genera of Choristidae and three species in two genera of Panorpodidae as outgroup taxa,and a total of 155 species in eight genera of Panorpidae as ingroup taxa.Three datasets were analyzed:1)182 morphological characters of adults,under Maximum Parsimony;2)1876 bp-long concatenated 28S,COI,and COII gene partial sequences,under Bayesian Inference;3)2058 bp-long concatenated morphological characters and DNA sequence data,under Bayesian Inference.The resultant phylogenetic trees are basically consistent in topology;however,the position of Leptopanorpa and the basal relationship of Panorpinae are controversial.The main conclusions are as follows:1)Panorpidae is a monophyletic group,and can be categorized into two major clades(Panorpinae and Neopanorpinae subfam.n.);2)both subfamilial clades are supported as monophyletic groups;3)in Panorpinae,the monophylies of Cerapanorpa,Dicerapanorpa,Megapanorpa,and Sinopanorpa are supported;while Panorpa is paraphyletic with these genera and needs further splitting;4)most species groups in Panorpa are supported as monophyletic clades and likely merit generic status;5)in Neopanorpinae subfam.n.,Neopanorpa is paraphyletic with Leptopanorpa and needs further revisions;the N.denticulata group and N.chillcotti group likely merit generic status.In the discussion part,phylogenetic relationships are compared and discussed among results inferred from different datasets and methods,and previous phylogenetic studies;diagnostic characters and evolutionary relationships are summarized for each lineage,providing more evidence for a further taxonomic revision.In Chapter IV,a taxonomic revision is presented for the world Panorpidae,with a total of 490 valid species(assigned into nine genera,with eight fossil species in two genera,and 482 extant species in eight genera),30 new synonyms,one new combination,and four species newly recorded from China.Based on the distinct morphological divergences and previous phylogenetic analyses,Neopanorpinae subfam.n.is erected to include Leptopanorpa and Neopanorpa,while the other seven genera are assigned into Panorpinae.Species groups and sections are reassigned:32 groups with ten sections in Panorpa,two groups in Dicerapanorpa,and eight groups in Neopanorpa.For each taxon,the following information is provided:Chinese common name,scientific name,citations(including type depositions and type localities),etymology,measurements,diagnosis,description,specimens examined,distribution,and illustrations,etc.Keys to subfamilies,sections,genera,and species,in addition to a checklist of the world Panorpidae,are also provided.In Chapter V,the phylogenetic relationships,the position of the fossil species,and the origin,evolution,and biogeography of Panorpidae are discussed based on the current analyses and previous studies.The main claims are as follows:1)The sister group-relationship between Panorpidae and Panorpodidae is rejected,but in current phylogenetic studies exclusively dealing with extant groups,it is practicable to consider these two families being sister taxa;the position of Leptopanorpa still needs more research;the monotypic genus(?)Baltipanorpa and seven extinct Panorpa species belonged to Panorpinae;2)Panorpidae very likely originated from East Asia;early divergences at the subfamilial and generic levels were probably associated with the colliding between Indian and Eurasian Plates,the subsequent uplifting of the Qinghai-Tibetan Plateau,the extrusion and escape of the Sundaland,and the orogeny of the Hengduan Mountains,etc.;while the speciation was mostly related to the climate fluctuations during the Pleistocene glacial periods;3)the independent dispersal events very likely happened at least two times for the Indonesian fauna,five times for the Japanese fauna,two times for the Palearctic fauna,and four times for the Nearctic fauna.