Orthogonius species and diversity in Thailand (Coleoptera, Caraboidea, Orthogoniini), a result from the TIGER project.

The carabid genus Orthogonius MacLeay is treated, based mainly on materials collected in Thailand through the TIGER project (the Thailand Inventory Group for Entomological Research). Among 290 specimens, 20 species are identified in total, 10 of them are new species: Orthogonius taghavianaesp. n. (Nakhon Nayok: Khao Yai National Park), Orthogonius coomanioidessp. n. (Phetchabun: Thung Salaeng Luang National Park), Orthogonius similarissp. n. (Phetchabun: Thung Salaeng Luang National Park; Loei: Phu Kradueng National Park), Orthogonius setosopalpigersp. n. (Phetchabun: Thung Salaeng Luang National Park), Orthogonius gracililamellasp. n. (Loei: Phu Kradueng National Park; Chaiyaphum: Tat Tone National Park), Orthogonius pseudochaudoirisp. n. (Phetchabum: Thung Salaeng Luang National Park; Nakhon Nayok: Khao Yai National Park), Orthogonius constrictussp. n. (Phetchabum: Thung Salaeng Luang National Park), Orthogonius pinophilussp. n. (Phetchabum: Thung Salaeng Luang National Park), Orthogonius varisp. n. (Cambodia: Siem Reap; Thailand: Ubon Ratchathani: Pha Taem National Park; Phetchabun: Thung Salaeng Luang National Park) and Orthogonius variabilissp. n. (Thailand: Phetchabun: Thung Salaeng Luang National Park; Nakhon Nayok: Khao Yai National Park; Phetchabun: Nam Nao National Park; China: Yunnan). In addition, Orthogonius mouhoti Chaudoir, 1871 and Orthogonius kirirom Tian & Deuve, 2008 are recorded in Thailand for the first time. In total, 30 species of Orthogonius have been recorded from Thailand, indicating that Thailand holds one of the richest Orthogonius faunas in the world. A provisional key to all Thai species is provided. A majority of Thai Orthogonius species are endemic. Among the ten national parks in which orthogonine beetles were collected, Thung Salaeng Luang holds the richest fauna, including 16 species.