Taxon sampling
A total of 87 individuals from 19 species were collected by hand or sweep net at night. Adults were preserved in 70% ethanol in the field. The morphological identifications prior to DNA extraction were made depanding on the male apex of abdomen and paraproct (Gorochov et al ., 2015). Samples of genus Diestramima were collected from twelve provinces in China Oriental realm, including Anhui, Chongqing, Fujian, Guangdong, Guangxi, Guizhou, Hubei, Hunan, Jiangxi, Sichuan, Yunnan and Zhejiang (Fig. 1). All widespread species in China and a cross-border species distributed in China and Vietnam have been collected. Moreover, we examined a large of additional specimens and relevant literature (Storozhenko, 1990; Gorochov, 1994, 2010; Liu & Zhang, 2001; Gorochov & Storozhenko, 2015; Qin et al ., 2016; Zhu & Shi, 2018; Wang et al ., 2019) of Rhaphidophoroidea for better understanding the morphological variations of species, to aid in accurate species determination. Thus, the present sampling is the almost comprehensive one for the phylogenetic analysis in terms of both taxonomy and distribution. All diagnostic characters were photographed by OLYMPUS DP27, and arranged using Adobe Photoshop CC (Fig. 2, Fig. 3).