Tridrepana subunispina is found in Yunnan (a landlocked province in the southwest of the People's Republic of China) and its forewings have a brown crescent patch below the apex while the hindwings have a curved indistinct postmedial line.
It is found in Yunnan, China. Yunnan () is a landlocked province in the southwest of the People's Republic of China. The forewings have a brown crescent patch below the apex, shaded with dark brown and with a series of grey spots inside. The hindwings have a curved indistinct postmedial line and the submarginal line is brown and wavy. 
