Systematic Study On Seven Genera Of The Subfamily Orthocladiinae From East Asia (Diptera: Chironomidae)

The seven genera of Orthocladiinae Chaetocladius, Heleniella,Heterotrissocladius, Krenosmittia, Limnophyes, Mesosmittia,Orthocladius, from East Asia, were poorly studied in the world. East Asiabelongs to the Sino-Indian Region (except Southeast Asia), which is oneof the largest area in B n rescu’s zoogeographic regionalization andrich in species diversity. This thesis is the first comprehensiverevised systematic study on the seven genera from East Asia. Thedissertation comprises three main sections: introduction,classification and bio-geographic analysis.In the section of introduction, the research history and currentresearch status of the seven genera are reviewed both in East Asia andworldwide; classification and morphological characters in each genus areintroduced together with the taxonomic status; material collection and handling in addition to investigation area are described. Objectives andsignificance of this study are also stated.In the section of classification,170species of the seven genera aredescribed in detail. Among the taxa,22species are described as new toscience;7species are newly recorded to the Oriental Region;2speciesare newly recorded to the Palaearctic Region;17species are recorded toChina for the first time;1species is recorded as male adults for the firsttime to China;5wrong recorded species in China of Wang (2000) and17wrong recorded species in Japan of Yamamoto (2004) are corrected.2new combinations are proposed. Synonyms of known taxa are listed inchronological order. The available data on geographical distribution arealso reported. Keys to species in the worldwide (1genus), in East Asia (5genera) and in China (1genus) are given. Generic characters ofrecognized genera in the dissertation are revised and amended.22species are described as new to science (including8species published in2011-2012): Chaetocladius absolutus sp. n., Chaetocladiustibetensis sp. n., Chaetocladius triquetrus sp. n., Heterotrissocladiusflectus Kong&Wang,2011, Heterotrissocladius quartus Kong&Wang,2011, Heterotrissocladius reductus Kong&Wang,2011, Limnophyesbicornis sp. n., Limnophyes ludingensis sp. n., Limnophyes minerus sp. n.,Limnophyes subtilus sp. n., Mesosmittia apsensis Kong&Wang,2011,Mesosmittia brevae Kong&Wang,2011, Mesosmittia gracila Kong&Wang,2011, Orthocladius (Eudactylocladius) brevis sp. n., Orthocladius(Eudactylocladius) fengensis sp. n., Orthocladius (Eudactylocladius)interctus sp. n., Orthocladius (Euorthocladius) albidus sp. n.,Orthocladius (Euorthocladius) flectus sp. n., Orthocladius(Euorthocladius) tibetensis sp. n., Orthocladius (Mesorthocladius)tornatilis Kong&Wang,2012, Orthocladius (Orthocladius) absolutusKong&Wang, Orthocladius (Symposiocladius) futianensis Kong&Wang,2012. 10species are newly recorded to Oriental Region (including4species published): Chaetocladius oyabevenustus Sasa et al., Limnophyestamakitanaides Sasa, Orthocladius (Orthocladius) nitidoscutellatusLundstr m, Orthocladius (Eudactylocladius) musester S ther,Orthocladius (Mesorthocladius) vaillanti Langton&Cranston(published), Orthocladius (Orthocladius) dorenus (Roback),Orthocladius (Orthocladius) manitobensis S the, Orthocladius(Symposiocladius) holsatus Goetghebuer (published), Orthocladius(Symposiocladius) lignicola Kieffer (published), Orthocladius(Symposiocladius) schnelli S ther (published).2species are newly recorded to Palaearctic Region: Mesosmittiaacutistyla S ther (published), Mesosmittia acutistyla S ther (published).17species are recorded for the first time to china（including7species published): Chaetocladius oyabevenustus Sasa et al.,Heterotrissocladius scutellatus Goetghebuer, Limnophyes tamakitanaides Sasa、 Mesosmittia acutistyla S ther (published), Orthocladius(Eudactylocladius) musester S ther, Orthocladius (Eudactylocladius)priomixtus S ther, Orthocladius (Eudactylocladius) sublettorumCranston, Orthocladius (Mesorthocladius) vaillanti Langton&Cranston(published), Orthocladius (Orthocladius) rhyacobius Kieffer,Orthocladius (Orthocladius) dorenus (Roback), Orthocladius(Orthocladius) excavatus Brundin, Orthocladius (Orthocladius)manitobensis S ther, Orthocladius (Orthocladius) nitidoscutellatusLundstr m, Orthocladius (Pogonocladius) consobrinus (Holmgren),Orthocladius (Symposiocladius) holsatus Goetghebuer (published),Orthocladius (Symposiocladius) lignicola Kieffer (published),Orthocladius (Symposiocladius) schnelli S ther (published).5wrong recorded species in China of Wang (2000) are corrected:Heleniella osarumaculata Sasa (Wang2000:636), Limnophyesfuscipygmus Tokunaga (Wang2000:636), Orthocladius (Orthocladius) obumbratus Johansen (Wang2000:637), Orthocladius (Orthocladius)saxicola Kieffer (Wang2000:637), Orthocladius (Orthocladius)yugashimaensis Sasa (Wang2000:637).17wrong recorded species in Japan of Yamamoto (2004) arecorrected: Krenosmittia yakylemea (Sasa&Suzuki)(Yamamoto2004:45), Limnophyes kibunefuscus Sasa (Yamamoto2004:45), Limnophyeskibunepilosus Sasa (Yamamoto2004:45), Limnophyes oiraquartus Sasa(Yamamoto2004:48), Limnophyes yakyefeus Sasa&Suzuki (Yamamoto2004:50), Orthocladius (Eudactylocladius) biwaniger Sasa&Nishino(Yamamoto2004:57), Orthocladius (Euorthocladius) oirasecundus Sasa(Yamamoto2004:58), Orthocladius (Euorthocladius) shoufukusextusSasa (Yamamoto2004:59), Orthocladius (Euorthocladius) tusimoopeusSasa&Suzuki (Yamamoto2004:59), Orthocladius (Orthocladius)chuzeseptimus Sasa (Yamamoto2004:59), Orthocladius (Orthocladius)filamentosus (Tokunaga)(Yamamoto2004:60), Orthocladius (Orthocladius) kamihiroi Sasa&Hirabayashi (Yamamoto2004:61),Orthocladius (Orthocladius) kamisemai Sasa&Hirabayashi (Yamamoto2004:61), Orthocladius (Orthocladius) seiryugeheus Sasa&Suzuki(Yamamoto2004:61), Orthocladius (Orthocladius) tamaputridus Sasa(Yamamoto2004:61), Orthocladius (Orthocladius) tamarutilus Sasa(Yamamoto2004:61), Orthocladius (Orthocladius) toyamakeleus Sasa(Yamamoto2004:61).1species are recorded as male adults for the first time to China：Limnophyes pentaplastus (Kieffer).2new combinations are proposed: Orthocladius (Eudactylocladius)yakyefeus (Sasa&Suzuki) Comb. n. and Psectrocladius toyamakeleus(Sasa) Comb. n.According to the genera and species distribution data (7genera and319species in the world), a preliminary biogeographic analysis is madebased on both B n rescu’s freshwater and Wallace’s traditional zoogeographic regionalizations. According to Sclater-Wallanceregionalization, it is obvious that the species distributed in PalaearcticRegion are regarded as dominant in the world (217species,68%ofspecies number of the world). Based on B n rescu’s freshwaterzoogeographic regionalization, these7genera in East Asia have6distributional categories on the specific lever in Sino-Indian Region. Thedata statistics shows East Asia has high species diversity (180species,56%of species number of the world;136endemic species,43%ofspecies number of the world). In East Asia, China has68species (21%ofspecies number of the world and40%of East Asia), including26endemic species (8%of species number of the world and19%of EastAsia). The data statistics reflects that East Asia has high species diversityin the world, and it could be one of the centers of origin and speciation ofthe Subfamily Orthocladiinae. B n rescu’s zoogeographic regionalizationand the traditional regionalization are compared. Based on the higher common species distribution in Oriental China and Japan (PalaeacticRegion), B n rescu’s zoogeographic delimitation is more reasonable thanthe traditional Sclater-Wallance regionalization for aquaticChironomidae.The list of incorrect identification and correction, geographicaldistribution chart of the seven genera, the species name indexes in bothChinese and Latin are provided as appendixes.All the Chinese specimens in this study (including type materials)are deposited in the Lab of Chironomidology, College of Life Sciences,Nankai University, China.