| abstract | A new species, Psilogamasus pentatideus Yao & Jin n. sp., is described based on adults from Hainan province, China. Taiwanoparasitus Tseng is newly synonymized with Psilogamasus Athias-Henriot. Four species, Taiwanoparasitus pentasetosus Tseng, 1995, Vulgarogamasus brachysternalis Ma & Lin, 2005, V. longascidiformis Ma & Lin, 2005, V. lingulatus Bai & Ma, 2013, are transferred to Psilogamasus as new combinations. A key to the known species of the genus is given and the diagnosis of the genus is revised. |