Pima tristriata sp. nov. is described as new to science based on specimens collected from the Ningxia Hui Autonomous Region, China, and P. boisduvaliella (Guenée, 1845) is also treated here for comparison. DNA barcodes of the two species are provided, together with a neighbor-joining tree for species delimitation. A key to the Holarctic species and a distribution map of the Chinese species are presented.