Male: body length 18.7–25.5 mm, width at humeri 4.0–6.0 mm. Female: body length 22.0–26.6 mm, width at humeri 5.0–6.5 mm. Body uniformly black-brown, with rusty tinge (especially in male), except bases of tibiae (about 1/3 to 1/2), tips of antennal segments IV-XI (increasing from IV to XI), and extreme tips of last segments of maxillary and labial palps which are reddish-brown, and ventral side of tarsi and base of mandible being brown.

Body elongate, slender. Head with dense rugose punctures, with mouthparts turned forward and somewhat downward. Last segment of maxillary palp expanded and obliquely truncate apically. Frons between eyes with narrow interrupted longitudinal suture. Antennae long; scape very thick in male and more slender in female, without a groove on basal half, in male with coarse rugose punctures (Fig. 41a), in female not rugose but with finer punctures (Fig. 42a); scape not reaching midlength of pronotum in either sex; pedicel very small; subsequent segments slender; in male 7^th, in female 8^th segment extends beyond tip of elytra; antennal segments with recumbent long hairs beneath. The relative length of antennal segments, male: 10.6:1:12.9:13.2:13.1:12.5:11.9:11.1:9.7:8.7:8.8 (variable in narrow range); female: 9.9:1:10.2:10.3:10.3:10.1:9.5:8.5:7.4:6.5:6.3 (variable in narrow range).

Pronotum broadest in middle, with acute conical lateral spines, near posterior and anterior margins with slight transverse constriction, with rugae on disc, and with dense minute punctures and dense gray pubescence. Scutellum not longer than width at base, apically rounded, with yellowish pubescence.

Elytra narrow, taper uniformly toward apex, length 3.0–3.4 times the total width at humeri, and anterior half with deep punctures forming several indistinct longitudinal rows. Abdominal ventrite V in female (Figs 26b, 34d) elongate, gently rounded posteriorly; in male (Figs 28b, 33d) distinctly emarginate, with minute tender closely recumbent hairs. Legs long and slender, mesotibiae (of both male and female) without apical protruding lobe.

Male terminalia (Figs 29–33): Tegmen (Fig. 32) approximately 5.0 mm in length; lateral lobes slender, length about 5 times the width, ventral side and apex with short setae; median lobe plus median struts (Fig. 29) slightly curved, longer than tegmen; the median struts less than 1/8 of the whole median lobe in length; apex of ventral plate bluntly pointed; internal sac bearing a basal armature (Fig. 29b) and two median rods of endophallus (Figs 30, 31), of which the strongly sclerotized one (coming from the gonopore) connected to a very long (much longer than the median rods) hair-like rod (inside ejaculatory duct, Fig. 30). Tergite VIII (Fig. 33) longer than broad, narrowed apically from middle, with rounded apex, apical half bearing short dorsal setae.

Female terminalia (Figs 34–36): Paraproct moderate in size, its baculi thick and long, straight and not bifurcate at base; valvifer indistinct; coxite with rough surface, each baculum very thick at base and narrowed towards apex; coxite lobes sclerotized at each inner part, with tactile hairs; stylus articulated to the tip of each coxite lobe (slightly laterally), sclerotized except for apex and bearing tactile hairs; dorsal baculi sinuate and longer than paraproct baculi; proctiger baculi long and almost straight. Spermathecal capsule (Figs 34–36) large, heavily sclerotized and of very intricate structure, its apical part narrow, strongly bent at middle and basally with a protrusion (in shape of a question mark “?”), basal part irregularly twisted and with rather broad protrusion to which attaches the spermathecal gland at the middle part. Tignum much shorter than half of abdomen. In one measured specimen, tignum was 4.4 mm for an adult with 12.0 mm abdomen length in ventral view.

The differences of the three species are shown in Table 1.

The name of the new species refers to its distribution in southeast China, instead of northeast China (which is the distribution of Distenia gracilis).

This species has been misidentified as Distenia gracilis sinceGressitt (1951).

It is the 29^th recorded species for the Chinese Disteniidae fauna (Lin et al. 2010; Lin and Murzin 2012).

One female from Mt. Wutaishan of Shanxi Province shows a strange dot on the distributional map. We believe that the distribution region will be extended after further survey.

China: Zhejiang Prov., Fujian Prov., Guangdong Prov., Jiangxi Prov., Shanxi Prov.

Holotype, male, Zhejiang, Xitianmushan, alt. 1200 m, 2008.VII.2, coll. Hao Huang (SNUC, ex CBWX). Paratypes: China, Zhejiang: 1 male, Xitianmushan, alt. 1300 m, 2009.IV.19 (larva), 2009.V.14 (adult), coll. Wenxuan Bi (CBWX); 1 male, Xitianmushan, alt. 1100 m, 2008.III.1 (larva), 2008.V.27 (adult), coll. Wenxuan Bi (CBWX); 1 female, Tianmushan nature reserve, alt. 1100 m, 2008.VII.30, coll. Yongxiang Wu (CJM); 1 female, China, Chekiang, Tien-mu-shan, 1937.VI.30, coll. E. Surnson (ZMMU); 1 female, Xitianmushan, alt. 1000m, 2012.VII.11, coll. Deyao Zhou (CZDY); 1 female, Tienmushan, 1937.VIII.3 (IZAS, IOZ(E)1859289); 2 males, same data (IZAS, IOZ(E)1859290-91); 2 males, same data but 1937.VIII.4 (IZAS, IOZ(E)1859292-93); 1 male, same data but 1937.VII.21 (IZAS, IOZ(E)1859288); 1 female, Longquan, Fengyangshan, Lu'ao village, alt. 1100 m, 2008.VII.31, coll. Wenxuan Bi (CBWX); Qingyuan county, Baishanzu nature reserve, alt. 1000 m, 2009.VII.25-VIII.5, coll. Zhizhou Yu (CYZZ). China, Fujian: 1 male, Chong’an, Sangang, 1979.VIII.14 (IZAS, IOZ(E)1859287); 1 male, Fujian, Wuyishan nature reserve, 2009.VII.10–15. coll. Ming Jin (CJM). China, Jiangxi: 1 female, Wuyishan nature reserve, Yejiachang station, alt. 900 m, 2004.VIII.2 (CCCC). China, Guangdong: 1 female, Ruyuan county, Nanling nature reserve, 2008-2009, coll. Lei Gao (CCCC).

China, Shanxi: 1 female, Wutaishan, alt. 2000 m, 1996.VII.17, coll. Wenzhu Li (IZAS, IOZ(E)1859062).