Five additions to the list of Sepsidae Diptera for Vietnam: Perochaeta cuirassa sp. n., Perochaeta lobo sp. n., Sepsis spura sp. n., Sepsis sepsi Ozerov, 2003 and Sepsis monostigma Thompson, 1869 Author Ang, Yuchen Author Meier, Rudolf text ZooKeys 2010 70 41 56 http://dx.doi.org/10.3897/zookeys.70.766 journal article http://dx.doi.org/10.3897/zookeys.70.766 1313-2970-70-41 Sepsis monostigma Thompson, 1869 Figs 15-17 Sepsis monostigma Thompson, 1869. Kongliga svenska fregatten Eugenies resa omkring Jorden, 2(1): 443. Material. ♂♂♀♀ (RMBR), Vietnam, Lao Cai Province, Sa Pa Valley. From ex culture established from ♀ collected from dung on cow farm, 4km NE of Sa Pa town [22°21'28.19"N; 103°51'53.35"E, elevation 1250m ASL]. Collected 15.VII.2010 (Ang Y). Figures 15-23. Various Sepsis forelegs and hypopygia. Sepsis monostigma :15 fore femur, posterior 16 fore tibia, posterior 17 hypopygium, dorsal. Sepsis sepsi : 18 fore femur, posterior 19 fore tibia, posterior 20 hypopygium, dorsal. Sepsis nitens : 21 fore femur, posterior 22 fore tibia, posterior 23 hypopygium, dorsal. Scale bars: 0.5mm. Taxonomic remarks. Sepsis monostigma is an Oriental species that resembles Sepsis pseudomonostigma Ursu, 1969 but is geographically exclusive from Sepsis pseudomonostigma (which has only been recorded in South and South-east Europe and Central Asia). Sepsis monostigma can be differentiated by the two long medioventral spines (one short spine in Sepsis pseudomonostigma ) on the fore femur (Fig. 15), lack of ventromedial spinules on the fore tibia (Fig. 16) and surstylus (Fig. 17) being much thinner than that in Sepsis pseudomonostimga . Distribution. China (Guandong), Taiwan, India (Jammu and Kashmir, Uttar Pradesh, West Bengal), Japan (Hokkaido Is., Honshu Is., Kyushu Is.), Korea, Philippines (Luzon Is.), Sri Lanka, South Russia (Amurskaya Oblast' , Irkutskaya Oblast' , Khabarovskiy Kray, Krasnoyarskiy Kray, Novosibirskaya Oblast' , Primorskiy Kray, Sakhalinskaya Oblast' ), Vietnam ( Lao Cai).