Systematics Of Lauxaniidae (Diptera:Lauxanioidea) From Southwest China

The family Lauxaniidae belongs to the superfamily Lauxanioidea, the Schizophora, the subordinate Acalyptrata, the suborder Cyclorrhapha, the order Diptera. It is one of the biggest Acalyptrata families and an important family of the superfamily Lauxanioidea. It is distributed in all the zoogrographical realms. Previous researches show that the Lauxanioidea is a near basal Acalyptrata superfamily, so the systematics of Lauxaniidae is a critical for revealing phylogeny of Acalyptrata superfamilies. The Lauxaniidae contains172genera2450species in3subfamilies in the world fauna Adults and larvae are recorded as fungal grazers and detritovores in leaf litter, decaying vegetation, and birds’ nests. They play an important role in degradating organic matter, protecting environments and keeping ecological balance. Moreover, the lauxaniids are sensitive to environmental changes and are utilized as a biological indicator of environmental changes in the agricultural ecosystem. Those characteristics of extensive distribution, habitat diversification and morphological diversity make it a major concern all over the world in recent years. Southwest China is one of the richest areas with generic and specific diversity of lauxaniids in the world, but the fauna of Lauxaniidae has not been comprehensively studied.The present dissertation deals with the systematics of Lauxaniidae from Southwest China. The research history and current situation of Lauxaniidae are recalled. The biology and ecology of lauxaniids are briefly introduced. The zoogeography of Lauxaniidae is briefly analyzed. It shows that single-region pattern is predominant; in the subfamily Homoneurinae, the Oriental region holds the most abundance in the generic and specific levels, as the subfamily Lauxaniinae in the Neotropical region; The results of statistics from the Chinese fauna show that the south China district is predominant both in the generic and specific levels.In the taxonomic section,176species in20subgenera from Southwest China are described, including1new genus,2newly recorded genera,109new species,5newly recorded species, among which117species are described with the taxonomically useful structures of male genitalia illustrated, and160species are taken photos of partial characteristics of the head, thorax and wing,In Homoneurinae,49new species,3newly recorded species and42known species from Southwest China are described:2new species,6known species in Cestrotus;5known species in Dioides;42new species,3newly recorded species,24known species in Homoneura;3new species,2known species in Noonamyia;1new species,4known species in Phobeticomyia;1new species,1known species in Prosopophorella.In Lauxaniinae,14genera (1new genara,2newly recorded genera),60new species,2newly recorded species and20known species from southwest China are described.1new genera is Chinensis gen. nov.(including1new species).2newly recorded genera is Trypetisoma (including8new species,1newly recorded species) and Trigonometopsis (including1new species).Others genera:1new species in Drapanephora; Lauxania (including3new species,1newly recorded species);2new species in Melanopachycerina;5known species in Dioides;43new species,2newly recorded species,21known species in Homoneura,3new species,2known species in Noonamyia,1new species,4known species in Phobeticomyia,1new species,1known species in Prosopophorella;25new species,9known species in Minettia;5new species,2known species in Neeotomima;2known species in Pachycerina;1new species in Sciasmomyia;1new species,3known species in Steganopsis;1new species in Xangelina;4new species,2known species in Luzonomyza;7new species,2known species in Tetroxyrhina;Prior to the research, the Chinese fauna includes31genera303species and Southwest Chinese fauna includes17genera111species, after the research, the Chinese fauna includes34genera417species and the Southwest Chinese fauna includes23genera235species,The keys to separate genera, species groups, species are provided.