Holotype : China • ♂; Yunnan Province, Xishuangbanna, Mengla County, Wuxiangguangchang; 21.92N, 101.11E; 21–24 Mar. 2019; leg. Chao Tong and Shenzhi Chen.

China • 1♀, same data as holotype.

Figures 1–7. 

Xya xishangbanna sp. nov. 1 body in dorsal view ♂ 2 body in lateral view ♂ 3 body in ventral view ♂ 4 body in dorsal view♀ 5 head in frontal view ♀ 6 end of abdomen in posterior view ♂ 7 gonopore in ventral view ♀. Scale bars: 1.0 mm.

Male. Habitus with bright or shiny surface. Head black with brown band along inner margin of compound eyes. Antennae moniliform, black, 10 segments, length of each antennomere almost equal to width. Compound eyes dark brown to black, 2 times broader than longer, rounded in front. Ocelli grayish white. Gena black.

Thorax. Pronotum black, width about 1.25 times length, yellow on ventral margin. Forewings blackish-brown, with pair of basal and medial brown spots. Hindwings yellowish-white, extending beyond the end of abdomen distinctly. Fore and mid legs dark brown with yellow spots. Hind legs with femora dark brown, dorsal margin black, with yellowish-white spots; hind tibiae yellowish-brown, with three (inside) and four (outside) pairs of articulated lamellae.

Abdomen. Abdomen black, gray along posterior margin of each segment. Apex of every sternite with distinct transverse white stripe. Cerci black, paraproctal lobe slightly lighter in coloration than cerci. Epiproct with bottom of the middle “v-shaped” crack in the upper part shallow, and sides straight (Fig. 13A). Female. Body larger than male in size. Abdominal segments black with posterior margin gray for each segment. Epiproct rounded. Subgenital plate margin with a notch. Others same as male.

Length of body: ♂ 5.63, ♀ 7.16. Length of fore wing: ♂ 1.59, ♀ 2.37. Length of hind wing: ♂ 4.84, ♀ 6.28. Length of hind femur: ♂ 3.76, ♀ 4.50.

China (Yunnan).

This species can be diagnosed by the shiny dark brown hind femora. It is most similar to X. leshanensis Cao et al. in the compound eyes with a narrow band along the inner margin. It can be distinguished from the latter by the body with dorsal surface not rough, but more shiny; the compound eyes with a prominent brown band along their inner margin on both sides; the hind femora dark brown, with a pair of white and yellow longitudinal spots; forewings with a pair of basal and apical brownish spots; the length of hind wing more than 4.0 mm; and the epiproct with shallow bottom of the middle “v-shaped” crack in the upper part, and straight sides. In X. leshanensis, the body surface is rough; the compound eyes bear a yellowish-white band along the inner margin; the hind femora are black, bearing four yellowish-white spots near the middle; the forewings have no spot; the length of hind wings is less than 4.0 mm; and the epiproct has deep “v-shaped” crack in the upper part with the sides curved (Fig. 13B). Major differences are listed in Table 1.

The specific epithet is named after Xishuangbanna, the type locality.

Holotype : China • ♂; Yunnan Province, Xishuangbanna, Mengla County, ♂, Wujiazhai; 22.05N, 100.89E; 21–24 Mar. 2019; leg. Chao Tong and Shenzhi Chen.

Figures 8–12. 

Xya yunnanensis sp. nov. 8 Body in dorsal view ♂ 9 Body in lateral view ♂ 10 Body in ventral view ♂ 11 Head in frontal view ♂ 12 End of abdomen in posterior view ♂. Scale bars: 1.0 mm.

Male. Head black, without band along inner margin of compound eye. Labial palpi black. Antennae filiform, black, 10 segmented, 10th segment dark fuscous, each segment widens from base to apex. Compound eyes grayish black. Three white ocelli. Gena below the compound eye black.

Thorax. Pronotum black, width about 1.2 times length, with reddish brown luster, white on lateral margin intermittently. Forewings black, with two obscure dirty white sub-rectangular patches at base and apex respectively. Hindwings white, black along posterior margin, about 5/6 length of abdomen. Fore legs yellowish-white; femora with black longitudinal stripe; tarsi with three yellowish-white distal spines. Mid legs black, with yellowish-white irregular markings on femora and tibiae. Hind legs with femora black, with a narrow yellowish-brown marking on basal 1/3 ventrally; semi-lunar process black, yellowish-brown at base; tibia yellowish-brown, darkens toward apex, with three (inside) and four (outside) pairs of articulated lamellae.

Abdomen. Abdomen black, white along posterior margin of each segment. Cerci with two segments, 1st segment black, white at base; 2nd segment pale fuscous, with sparse long white setae. Stylus black on outer side, pale fuscous on inner side, shorter than cerci. Epiproct with shallow “v-shaped” crack in the upper part, bottom of the side edge has a sharply angled protrusion, and width of the narrow lower anchor-shaped base is less than 1/2 the width of the upper one (Fig. 13C).

Unknown.

Length of body: ♂ 5.43. Length of fore wing: ♂ 1.28. Length of hind wing: ♂ 2.47. Length of hind femur: ♂ 3.72.

China (Yunnan).

This species can be diagnosed by the compound eye bearing no narrow band along the inner margin. It is most similar to X. sichuanensis Cao et al. in having four markings on the forewing, and lacking a patch on the pronotum dorsally. It can be distinguished from the latter by the compound eyes without a narrow band along the inner margin; with no ring around the median ocelli; the black gena below the compound eye; the forewing with obscure dirty white sub-rectangular patches, the length of fore wing about 1.28 mm; the white hindwing; and the epiproct with bottom of the side edge with a sharply angled protrusion and the narrow lower anchor-shaped base less than 1/2 the width of the upper one. In X. sichuanensis, the compound eyes bear a narrow yellow band along inner margin; bears a yellow ring around the median ocelli; the gena below the compound eye is yellow; the forewings have yellow triangular patches, the length of fore wing is about 0.9–1.1 mm; the hindwings are yellow; the epiproct with bottom of the side edge without a sharply angled protrusion and the large lower anchor base about 4/5 the width of the upper one (Fig. 13D). Major differences are listed in Table 2.

The specific epithet is named after Yunnan, the type locality.

These two new species are found along waterways and under mud and stones amidst many different plants and shrubs (Fig. 14). They seem to be living near humid sand with water nearby. The adults were collected during the month of August. They can jump from both the ground and water.

Figure 13. 

The line diagrams for male epiproct of four Xya species. A Xya xishangbanna sp. nov. B Xya leshanensis C X. yunnanensis sp. nov. D X. sichuanensis.

Figure 14. 

Landscape of habitat in Wuxiangguangchang (A, B) and in Wujiazhai (C, D) in Xishuangbanna, Yunnan, China.