Ephemera (Sinephemera) separigata Bae, 1995

Lei, Zhi-Ming & Zhou, Chang-Fa, 2024, The subgenus Sinephemera Kluge, 2004 in China (Ephemeroptera: Ephemeridae: Ephemera Linnaeus, 1758), Zootaxa 5517 (1), pp. 1-68 : 54-55

Ephemera (Sinephemera) separigata Bae, 1995 ( Figs 54–55 , 64 )

Ephemera strigata — Yoon and Bae, 1985: 98 (in part). Ephemera separigata Bae, 1995: 160 (all stages; holotype: male imagine from Korea). Ephemera separigata —Bae et Liu, 1999: 5 (nymph, first record from China); Quan et al., 2002: 250 (nymph, China); Hwang et al., 2008: 164 (list, not including China); Zhou, 2013: 187 (list); Zhou et al., 2015: 235 (list); Tiunova et Semenchenko,

2022: 94 (nymph, COI sequence, Russia). Ephemera (Sinephemera) separigata — Kluge, 2004: 235 (subgeneric combination).

Description (see Bae, 1995).

Diagnosis: Nymph: (1) two mandibular tusks subequal in length, shorter than head ( Figs 54 , 55A ); (2) length and width of frons subequal, or length slightly longer than wide; (3) lateral margins of frons slightly convex, anterior margin of frons shallowly concave ( Fig. 55A ); (4) three ocelli connected by black stripes ( Figs 54 , 55A ). (5) Some setae on posterior margins of fore wingpads, metathorax and tergite I; (6) tergite I with median ridge ( Fig. 55B ). (7) Gills I–V located at posterolateral angle of tergites, gill VI–VII located at middle of tergite lateral margin. (8) Stripe pattern on abdominal tergites ( Fig. 54 ): tergites I–X with a pair of black stripes near lateral margins. Stripes on tergites I–IV somewhat oblique to nearly straight, those on tergites V–X almost straight ( Figs 54A, C ). Generally looking, its abdomen has two parallel black stripes near lateral margins of tergites ( Figs 54A, C ). Sternites II–IX with pair of chocolate to black stripes, progressively longer from anterior to posterior segments ( Figs 54B, D ). Posterior margins of tergites and sternites pale. Hindcoxae pale.

Male imagine: (1) Tergites and sternites of abdomen have similar stripes as in nymph. (2) Penes slender, not fused but close, apices of them divergent and slightly sclerotized ( Fig. 55C ). (3) Only few crossveins of stigmata in forewings branched.

Female imagine: Tergites and sternites of abdomen have similar stripes as in nymph.

Comparison: The color pattern of this species is similar to E. rubrogata sp. nov. Generally, this species has black stripes on pale body, while E. rubrogata sp. nov. has red stripes on reddish body. See further discussion under E. rubrogata sp. nov.

The color pattern and genitalia of E. separigata are also similar to E. strigata . But all tergite stripes of E. strigata are somewhat oblique or nearly triangular, stripes on tergites VIII–X are lighter than others ( Figs 60 , 62 ). Futhermore, in E. strigata , penes are mostly fused together. In contrast, abdominal tergites of E. separigata has two straight lateral lines ( Fig. 54 ), and its penes ( Fig. 55C ) are slender and straighter than in E. strigata ( Fig. 62E ).

Remarks: Bae and Liu (1999) and Quan et al. (2002) reported this species in China, but Hwang et al. (2008) stated clearly at that time, that this species was known from Korea only. So here is the first confirmable report of this species in China. Tiunova & Semenchenko (2022) found it in Far East of Russia.

Material examined: China: 5 nymphs, Eaizi river , Caohe town , Bengxi county, Liaolin Province, 124.23829 079°E, 41.12093957°N, 518 m, leg. Xin-He Qiang, 2023- VII- 26; 6 nymphs, Aihe river , Saima town , Fengcheng county , Liaolin province, leg. Xin-He Qiang, 2023- VII-27 .

The holotype and paratypes of this species are deposited in Seoul Women’s University , Korea (Bae, 1995) .

Distribution ( Fig. 64 ): China (Jilin, Liaolin), Korea, Russia.

Figures

FIGURE 54. Nymphs of Ephemera separigata. A. male (dorsal view); B. male (ventral view); C. female (dorsal view); D. female (ventral view).

FIGURE 55. Morphology of Ephemera separigata. A. anterior part of nymph (dorsal view); B. nymphal abdominal tergites I–II (lateral view, red arrow indicating the median ridge of tergite I); C. male imaginal genitalia (ventral view).

FIGURE 60. Nymphs of Ephemera strigata. A. female (dorsal view); B. female (ventral view); C. male (dorsal view); D. male (ventral view).

FIGURE 62. Imagines of Ephemera strigata. A–D: female: A. dorsal view; B. ventral view; C. lateral view; D. abdominal segments I–II (lateral view, red arrows indicating the median tergites I and II); E. male genitalia (ventral view).

FIGURE 64. Distribution map of 13 Sinephemera species in China. Green: E. shengmi; yellow: E. separigata, E. japonica, E. strigata; Blue line: E. obliqua sp. nov.; blue dot: E. bistria sp. nov. and E. purpurata; shallow blue dot: E. rubrogata sp. nov.; purple: E. rubera sp. nov.; red line: E. cornea sp. nov.; red dot: E. axillaris and E. pictipennis; azure: E. pictiventris.