A Taxonomic Study On The Genus Omalium, Eusphalerum And Amphichroum (Coleoptera: Staphylinidae: Omaliinae) Of China

The family Staphylinidae is in the order Coleoptera and the class Insecta. Nearly 44000 species of this family have been known, and they are widely distributed all over the word. Omaliinae is one of the subfamily in Staphylinidae. About 1500 species of this subfamily have been known. They live at variety habitats including mountains, fields and so on. They have a wide range of food-habits, some groups have evolved as mycophagous, saprophagous, carpophagous, pollinophagous and so on. Staphylinidae has a close relationship with human and is distinctly important natural resource.Omalium, Eusphalerum and Amphichroum are three genera of subfamily Omaliinae. Omalium was established by Gravenhorst in 1802 with the type species Staphylinus rivularis Paykull. Until now 139 species of the genus have been known to the world. There are 3 species known in China, and they are all in the Mainland. Eusphalerum was established by Kraatz in 1857 with the type species Anthobium triviale Erichson. Up to the present 260 species of the genus have been studied all over the world. There are 46 species known in China, of which 32 in the Mainland,14 in Taiwan. Amphichroum was established by Kraatz in 1857 with the type species Lathrimaeum canaliculatum Erichson. Up to now only 15 species of the genus have been known all over the world. There are 3 species known in China, and they are all in the Mainland.However, taxonomic study on these three genera in China are only some sporadic studies but without systematic researches. Most of the Chinese known species were reported or recorded by foreign scholars and many type specimens were also deposited overseas. So there are great difficulties for us to study Chinese groups.China has diversity geographical environment and bestrides both Palaearctic and Oriental regions. The Omalium, Eusphalerum and Amphichroum resources are very abundant. In order to clarify these insect resources in China, the author selected this as the topic of his MS thesis. The study was based on the consulting all related literature and careful examinations of 615 specimens collected from Chongqing, Sichuan, Zhejiang, Qinghai, Ningxia, Shaanxi, Yunnan, Anhui, Shanghai, Hubei, Xizang and so on. The conclusions of my study are summed as below:1. This thesis was the first systematic study on the species of Omalium, Eusphalerum and Amphichroum from China.2. In the aggregate,10 species of Omalium in China were recognized, of which 9 species were diagnosed as new to science; 10 species of Eusphalerum in China were recognized, of which 8 species were diagnosed as new to science; 7 species of Amphichroum in China were recognized, they were all diagnosed as new to science3. All species were described in detail, with the collecting data and distribution of each species. The color photos of all the species were given and the diagnostic characters were illustrated. The research history was also given for known species.4. The key to the species of Omalium and Amphichroum of China was presented, and the key to the species groups of Eusphalerum of China mainland was provided.5. A catalog of the genus Omalium, Eusphalerum and Amphichroum of the world was given.6. A database including all the studied species of the genus Omalium, Eusphalerum and Amphichroum all over the world was delicately built.