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

The four genera of Orthocladiinae Metriocnemus, Parametriocnemus, Paraphaenocladius, Smittia, from East Asian area, were poorly studied in the world. East Asia belongs to the Sino-Indian Region (except Southeast Asia), which is one of the largest area in Banarescu’s zoogeographic regionalization and rich in species diversity. This thesis is the first comprehensive revised systematic study on the four genera from East Asian area. The dissertation comprises three main sections:introduction, classification and bio-geographic analysis.In the section of introduction, the research history and current research status of the four genera are reviewed both in East Asia and worldwide; classification and morphological characters in each genus are introduced together with the taxonomic status; material collection and handling in addition to investigation area are described. Objectives and significance of this study are also stated.In the section of classification,100species of the four genera are described in detail. Among the taxa,3species are described as new to science;4species are desribed as new synonym name to sicence;13species are newly recorded to the Oriental Region;1species are newly recorded to the Palaearctic Region;18species are recorded to China for the first time;2wrong identified species recorded in China of Wang (2000) and2wrong identified species recorded in Japan are corrected. The available data on geographical distribution are also reported. Keys to species of4genera in the in East Asia are given. Generic diagnostic characters by Cranston et al (1989) are revised and amended in the dissertation.3species are described as new to science (published in2013-2014): Metriocnemus calcaneum Li&Wang2014, Parametriocnemus fortis Li et Wang,2013, Parametriocnemus vittatus Li et Wang,2013.4species are desribed as new synonym name to sicence:Parametriocnemus isigageheus (Sasa&Suzuki) syn.n., Parametriocnemus tusimoveweus(Sasa&Suzuki) syn.n., Smittia itachipennis Sasa&Kawai syn.n., Smittia togaquirea Sasa&Okazawa syn.n.. 13species are newly recorded to Oriental Region (including10species published):Metriocnemus beringensis (Cranston&Oliver)(published), Metriocnemus bilobatus Makarchenko&Makarchenko (published), Metriocnemus caudigus Saether (published), Metriocnemus intergerivus S(?)ther (published), Metriocnemus tamaokui Sasa (published), Metriocnemus tristellus Edwards (published), Parametriocnemus lundbeckii (Johannsen), Parametriocnemus scotti (Freeman)(published), Smittia alpilonga Rossaro&Lencioni, Smittia celtica Rossaro&Delettre, Smittia contingens (Walker), Smittia hidakaijea Sasa&Suzuki, Smittia seiryuwexea Sasa, Suzuki&Sakai.1species is newly recorded to Palaearctic Region:Parametriocnemus scotti (Freeman)(published).18species are recorded for the first time to China (including10species published):Metriocnemus albolineatus (Meigen)(published), Metriocnemus beringensis (Cranston&Oliver)(published), Metriocnemus bilobatus Makarchenko&Makarchenko (published), Metriocnemus caudigus S(?)ther (published), Metriocnemus intergerivus Saether (published), Metriocnemus tamaokui Sasa (published), Metriocnemus tristellus Edwards (published), Parametriocnemus brundini Sinharay&Chaudhuri (published), Parametriocnemus lundbeckii (Johannsen), Parametriocnemus ornaticornis (Kieffer)(published), Parametriocnemus scotti (Freeman)(published), Paraphaenocladius pusillus S(?)ther&Wang, Smittia alpilonga Rossaro&Lencioni, Smittia celtica Rossaro&Delettre, Smittia indica Chaudhuri&Bhattacharyay, Smittia hidakaijea Sasa&Suzuki, Smittia ressi Rossaro&Orendt, Smittia seiryuwexea Sasa, Suzuki&Sakai.2wrong recorded species in China of Wang (2000) are corrected:Metriocnemus gracei Edwards (Wang2000:637)should be Metriocnemus tristellus Edwards, Smittia truncatoauda (Tokunaga)(Wang2000:637) should be Smittia aterrima (Meigen).2wrong description species in Japan are corrected:Parametriocnemus famiheius (Sasa)"without anal point" should be "with strong anal point", Smittia hidakaijea Sasa&Suzuki "BR30.54" should be "BR35.30".According to the genera and species distribution data (4genera and202species in the world), a preliminary biogeographic analysis is made based on both Banarescu’s freshwater and Wallace’s traditional zoogeographic regionalizations. According to Sclater-Wallance regionalization, it is obvious that the species distributed in Palaearctic Region are regarded as dominant in the world (137species,68%of species number of the world). Based on Banarescu’s freshwater zoogeographic regionalization, these4genera in East Asia have6distributional categories on the specific lever in Sino-Indian Region. The data statistics shows East Asia has high species diversity (100species,50%of species number of the world;83endemic species,41%of species number of the world). In East Asia, China has43species (21%of species number of the world and41%of East Asia), including5endemic species (2%of species number of the world and5%of East Asia). The data statistics reflects that East Asia has high species diversity in the world, and it could be one of the centers of origin and speciation of the Subfamily Orthocladiinae. Banarescu’s zoogeographic regionalization and the traditional regionalization are compared. Based on the higher common species distribution in Oriental China and Japan (Palaeactic Region), Banarescu’s zoogeographic delimitation is more reasonable than the traditional Sclater-Wallance regionalization for aquatic Chironomidae.The list of incorrect identification and correction, geographical distribution chart of the four genera, the species name indexes in both Chinese 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.