Ephemera (Sinephemera) strigata Eaton, 1892

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 : 58-64

Ephemera (Sinephemera) strigata Eaton, 1892 ( Figs 60–62 , 64 )

Ephemera strigata Eaton, 1892: 302 (male and female imagines, male subimagine; syntypes from Japan).

Ephemera strigata — Kimmins, 1960: 309 (male imagine) [designation and figure of lectotype]; Kimmins, 1971: 321 (lectotype depository); Tshernova et al., 1986: 105 (key for imagine); You et Gui, 1995: 110 (male imagine); Zhang et al., 1995: 75; Ishiwata, 2001: 58; Quan et al., 2002: 250; Bae and Liu, 1999: 5; Hwang et al., 2008: 164 (list); Zhou, 2013: 187 (list); Zhou et al., 2015: 235 (list); Kawai and Tanida, 2005: 51 (key for imagine). Tshernova, 1973: 332 (mentioned from Amur river, maybe the first record from China). Horasawa 1931: 34 (first description of nymph); Imanishi, 1940: 175 (nymph, Korea).

Ephemera kuwamayai Navás, 1919: 158 (male imagine from Tokyo, Japan) (synonymized by Ishiwata, 2001: 58).

Ephemera iwatensis Matsumura, 1931: 1467 (female imagine) (synonymized by Ishiwata, 2001: 58).

Ephemera jezonica Matsumura, 1931: 1467 (male and female imagine) (synonymized by Ishiwata, 2001: 58).

Ephemera (Sinephemera) strigata — Kluge, 2004: 235 (subgeneric combination).

Description (see Eaton, 1892 and Kluge, 2004).

Diagnosis: Nymph: two mandibular tusks subequal in length ( Figs 60 , 61A ); length and width of frons subequal, or slightly longer than wide, lateral margins of frons straight; two projections of frons slightly convergent, or straight, or divergent ( Fig. 61A ); three ocelli connected by black stripes ( Figs 60A, C , 61A ). Gills I, VI and VII located at middle of lateral margins of tergites, gills II–V at posterolateral angle. Stripe pattern on abdomen: tergites I–IX with pair of oblique stripes enlarged progressively from anterior to posterior and never meet at middle ( Figs 60A, C ); sternites II–IX with pair of submedian oblique stripes ( Figs 60B, D ); those stripes on segment X indistinct in most cases ( Fig. 60 ). Margins of tergites and sternites without stripes. Generally looking, abdomen has two markings on each tergite and sternite ( Fig. 60 ). Tergites I–II have very shallow median ridges ( Fig. 61B ).

Male imagine: Tergites and sternites of abdomen have stripes similar to that of nymph. Penes half fused, apical 1/3 slightly divergent, forming V-shaped notch between them; apex of penes slightly sclerotized ( Fig. 62E ).

Female imagine: Tergites and sternites of abdomen have stripes similar to that of nymph and male imagine ( Figs 62A–C ). Tergites I–II of abdomen with very shallow median ridges ( Fig. 62D ).

Comparison: This species can be identified by two independent oblique (sometime triangular) stripes or markings on abdominal tergites ( Figs 60 , 62 ). The male penes are unique in basal half fusing but apical half slightly diverged ( Fig. 62E ).

The species E. cornea sp. nov., E. japonica , E. obliqua sp. nov. and E. pictiventris also have two oblique stripes on tergites but they usually have more submedian stripes or pigmented midline on tergites VII–IX at least. The stripes of E. pictiventris are usually longer and slender than those of E. strigata , and their penes are totally different (slender and separated penes in E. pictiventris ).

Remarks: The color pattern of this species is close to E. separigata (see its discussion section). It is suspected that the report of E. separigata in China by Bae and Liu (1999) and Quan et al. (2002) are actual E. strigata because this distribution was not included in the report of Hwang et al. (2008).

Material examined: China: 20 nymphs, Gunan village, Erguna county , Inner Mongolia, leg. Chang-Fa Zhou, Hui Xie & Shi-Lei Wang, 2007-VIII-9 ; 25 nymphs, Genghe river, Genghe city, Inner Mongolia, Hui Xie & Shi-Lei Wang, 2007-VIII-10; 1 ♀ imagine, Mangui town, Genghe city, Inner Mongolia, Hui Xie & Shi-Lei Wang, 2007- VIII-12 ; 3 nymphs, Huma river, Huma county , He-Long-Jiang province, Hui Xie & Shi-Lei Wang, 2007-VIII-17 ; 3 nymphs, Er-Dao-Bai-He town, Fusong county , Jilin Province, leg. Gu Zhao & Shi-Lei Wang, 2008- VII- 24 ; 1 nymph, Song-Jiang-He town, 2008-VII-27 – 28, other information same as the former; 1 nymph, Hunhe river , Liaolin Province, leg. Yuan Zhang & Xing Gao, 2014-IX ; 15 nymphs, Tai-Zi river, others same as the former; 1 nymph, Song-Hua-Jiang river, Manjiang town , Jilin province, Xu-Hong-Li Zheng, 2022-VIII-10 .

The lectotype of this species is deposited in the British Museum ( Kimmins, 1971).

Distribution ( Fig. 64 ): Northeastern China; Japan, Korea, Mongolia, Russia.

Key to the male imagines of the species in the subgenus Sinephemera

1 Segment I of forceps relatively long, ca. half length of segment II; penes short, only tips of them surpassing styliger plate ( Figs 11E–F , 58G–H , 63C ).................................................................................. 2

- Segment I of forceps relatively short, less than 1/4 to 1/3 of the length of segment II; penes long, largely surpassing the styliger plate (as Figs 4H , 42D )................................................................................. 4

2 Most lateral portions of tergites I–IX brown to black ( Figs 9A , 10A–B )...................... Ephemera bistria sp. nov.

- Most lateral portions of tergites I–IX pale to amber, without other pigments (as Figs 56A , 57A–B , 63B )................ 3

3 Tergite I without dot or stripe ( Fig. 57A ); distributed in Asia..................................... Ephemera shengmi

- Tergite I with two dots or short stripes ( Fig. 63B ); distributed in Europe........................... Ephemera glaucops

4 Styliger plate with a distinct median cleft ( Figs 53E–F )....................................... E. rubrogata sp. nov.

- Styliger plate slightly concave, straight or convex but without clear median cleft (as Figs 17I , 30G ).................... 5

5 Tergites VI–IX with brown to black midline (as Fig. 20A )...................................... Ephemera japonica

- Tergites VI–IX with a pair or pairs of submedian stripes but without pigmented midline (as Fig. 24E ).................. 6

6 Tergites I–IX with two pairs of red submedian longitudinal stripes ( Fig. 46A ); most wings with red markings ( Figs 47A–B )........................................................................................ E. rubera sp. nov.

- Tergites I–IX with oblique markings near lateral margins (as Figs 16A–B ); wings with variable markings (as Figs 17D–F )... ................................................................................................... 7

7 Tergites I–II with one pair of oblique stripes, tergites III–IX with three pairs of submedian longitudinal stripes (as Figs 3A , 43A )............................................................................................... 8

- Tergites I–V or I–IX with oblique to straight stripes near lateral margins (as Figs 16A–B )............................ 9

8 Forewings with red dots other than transverse band, hindwings with red median dots or markings ( Fig. 42A, E, F )............................................................................................ Ephemera purpurata

- Forewings with transverse band only, hindwings without dots ( Figs 4A–C ).......................... Ephemera axillaris

9 Tergites I–V with oblique stripes near lateral margins ( Fig. 29A )................................ Ephemera pictipennis

- Tergites I–IX with oblique to straight stripes near lateral margins (e.g., Figs 36A , 54A )............................. 10

10 Tergites I–IX with straight stripes near lateral margins (as Fig. 54A )............................. Ephemera separigata

- Tergites I–IX with oblique stripes near lateral margins (as Fig. 36A )............................................ 11

11 Tergites VII–IX with one pair of oblique stripes (as Fig. 36A )................................................. 12

- Tergites VII–IX with three pairs of stripes (as Fig. 16A )...................................................... 13

12 Two penes independent and separated ( Fig. 37H ).............................................. Ephemera strigata

- Most parts of two penes closely located ( Fig. 62E )............................................. Ephemera strigata

13 Penes much longer than segment I of forceps ( Figs 17H–J )................................ Ephemera cornea sp. nov.

- Penes slightly longer than segment I of forceps ( Fig. 25F )................................ Ephemera obliqua sp. nov.

Key to the female imagines of the species in the subgenus Sinephemera

1 Tergites VII–IX with brown to black midline ( Fig. 20A )....................................... Ephemera japonica

- Tergites VII–IX with a pair or three pairs of stripes but without pigmented midline................................. 2

2 Sternites I–IX or II–IX with a pair of straight stripes (as Fig. 57D ).............................................. 3

- Sternites I–IX or II–IX with a pair of oblique stripes (as Fig. 36D ).............................................. 5

3 Stripes on sternites distinct, relatively wide ( Fig. 10D ).................................... Ephemera bistria sp. nov.

- Stripes on sternites indistinct, relatively narrow (as Fig. 57D ).................................................. 4

4 Tergite I without dot or stripe ( Fig. 57C )..................................................... Ephemera shengmi

- Tergite I with two dots or short stripes (as Fig. 63B )........................................... Ephemera glaucops

5 Tergites I–II with one pair of oblique stripes, tergites III–IX with three pairs of submedian longitudinal stripes (as Fig. 3D ).. ................................................................................................... 6

- Tergites I–V or I–IX with stripes but never with three pairs of longitudinal stripes.................................. 7

6 Forewings with red dots other than transverse band, hindwings with red median dots to markings ( Fig. 42B )................................................................................................. Ephemera purpurata

- Forewings with transverse band only, hindwings without dots ( Fig. 2B )............................ Ephemera axillaris

7 Tergites VII–IX with one pair of straight stripes near lateral margins in dorsal view (as Figs 29D , 52C )................. 8

- Tergites VII–IX with one pair or more oblique stripes in dorsal view (as Fig. 24E )................................. 11

8 Whole forewings almost brown to red (as Fig. 51B ).......................................................... 9

- Outer half of forewings pigmented brown at most ( Fig. 31D ).................................................. 10

9 Wings with several distincgt reddish markings (as Fig. 47A )................................................................................. E. rubera sp. nov. (female unknown, but they are assumed having similar color to males)

- Whole wings tinged with amber ( Fig. 51B ).......................................... Ephemera rubrogata sp. nov.

10 Outer half of forewings pigmented brown ( Fig. 31D )......................................... Ephemera pictipennis

- Forewings with median band only........................................................ Ephemera separigata

11 tergites VII–IX with one pair of oblique stripes only (as Fig. 36C ).............................................. 12

- Tergites VII–IX with more than one pair of stripes (as Fig. 16D )............................................... 13

12 Wings with dots other than median band..................................................... Ephemera strigata

- Wing without any dot, median band indistinct ( Fig. 35B )..................................... Ephemera pictiventris

13 Lateral margins of tergites I–IX or I–X without pigments ( Fig. 16F )............................... E. cornea sp. nov.

- Lateral margins of tergites VII–IX or VIII–IX black ( Fig. 24D )................................... E. obliqua sp. nov.

Key to the mature nymphs of the species in the subgenus Sinephemera

1 Tergites I–II with one pair of oblique stripes, tergites III–IX with three pairs of submedian longitudinal stripes (as Figs 1A, C ) ................................................................................................... 2

- Tergites I–V or I–IX with variable markings but never with three pairs of submedian stripes.......................... 3

2 Two mandibular tusks asymmetrical, left one much longer than right one ( Figs 39 , 40A )............. Ephemera purpurata

- Two mandibular tusks almost symmetrical ( Figs 1A–E )......................................... Ephemera axillaris

3 Tergites VII–IX with brown to black midline ( Fig. 19A, C )..................................... Ephemera japonica

- Tergites VII–IX with a pair or pairs of stripes but without pigmented midline...................................... 4

4 Sternites I–IX or II–IX with a pair of straight stripes (as Figs 6B, D )............................................. 5

- Sternites I–IX or II–IX with a pair of oblique stripes (as Figs 60B, D )............................................ 7

5 Stripes on sternites distinct, relatively wide ( Figs 6B, D ).................................. Ephemera bistria sp. nov.

- Stripes on sternites indistinct, relatively narrow (as Figs 57B, D )................................................ 6

6 Tergite I without dot or stripe (as Figs 57A, C )............................................... Ephemera shengmi

- Tergite I with two dots or short stripes ( Fig. 63A )............................................. Ephemera glaucops

7 Only tergites I–IV or I–V with a pair of oblique stripes or dots ( Fig. 27A )................... Ephemera pictipennis (male)

- Tergites I–IX with stripes (as Fig. 27C ).................................................................... 8

8 Tergites VII–IX with one pair or more straight stripes in dorsal view (as Figs 45A , 54A, C )........................... 9

- Tergites VII–IX with one pair or more oblique stripes in dorsal view (as Figs 60A, C ).............................. 12

9 Tergites with red stripes (as Fig. 48A ).................................................................... 10

- Tergites with brown to black stripes (as Fig. 54A, C )........................................................ 11

10 Tergites I–IX with two pairs of stripes ( Fig. 45A )........................................ Ephemera rubera sp. nov.

- Tergites I–IX with one pair of stripes ( Fig. 48A )...................................... Ephemera rubrogata sp. nov.

11 Sternites I–III with indistinct stripes ( Figs 54B, D )........................................... Ephemera separigata

- Sternites I–III with distinct stripes ( Figs 27B, D ).............................. Ephemera pictipennis (female, in part)

12 Tergites I–VI with more than one pair of stripes ( Fig. 27C )...................... Ephemera pictipennis (female, in part)

- Tergites I–VI without distinct stripe other than lateral pair ( Figs 33A, C )........................................ 13

13 Tergites VII–IX with one pair of oblique stripes only (as Figs 33A, C ).......................................... 14 - Tergites VII–IX with more than one pair of stripes (as Figs 13A, C )............................................ 15

14 Length of frons subequal to width in dorsal view ( Fig. 61A )..................................... Ephemera strigata

- Frons clearly longer than wide in dorsal view ( Fig. 34A )..................................... Ephemera pictiventris

15 Mandibular tusks clearly longer than head in dorsal view ( Fig. 14A )......................... Ephemera cornea sp. nov.

- Mandibular tusks clearly shorter than head in dorsal view ( Fig. 22A )....................... Ephemera obliqua sp. nov.

Figures

FIGURE 1. Larva of Ephemera (Sinephemera) axillaris. A–D: habitus:A. male (dorsal view); B. male (ventral view); C. female (dorsal view); D. female (ventral view); E. Head (dorsal view); F. abdominal segments I–II (lateral view, red arrows indicating the median tergal spines and ridges). Scale bar=1 mm.

FIGURE 2. Imagines of Ephemera axillaris (lateral view). A. male; B. female.

FIGURE 3. Imagines of Ephemera axillaris. A–C: male: A. dorsal view; B. ventral view; C. lateral view; D–F: female: D. dorsal view; E. ventral view; F. lateral view.

FIGURE 4. Male imagine of Ephemera axillaris. A. forewing; B. A1 area of forewing enlarged; C. hindwing; D. foreleg; E. midleg; F. hindleg; G. abdominal segments I–II (lateral view, red arrows indicating the median tergites); H. genitalia (ventral view); I. apex of right penis enlarged (ventral view).

FIGURE 6. Nymphs of Ephemera bistria sp. nov. A. male (dorsal view); B. male (ventral view); C. female (dorsal view); D. female (ventral view).

FIGURE 9. Lateral view of Ephemera bistria sp. nov. imagine. A. male; B. female.

FIGURE 10. Imagines of Ephemera bistria sp. nov. A. male (dorsal view); B. male (ventral view); C. female (dorsal view); D. female (ventral view).

FIGURE 11. Male imagines of Ephemera bistria sp. nov. A. forewing; B. base of forewing enlarged; C. hindwing; D. abdominal segments I–III (lateral view, red arrows indicating the median tergites I and II); E. genitalia (ventral view); F. apex of left penis enlarged (ventral view). Scale bar=1 mm.

FIGURE 13. Nymphs of Ephemera cornea sp. nov. A. male (dorsal view); B. male (ventral view); C. female (dorsal view); D. female (ventral view).

FIGURE 14. Nymphs of Ephemera cornea sp. nov. A. head (dorsal view); B. segments I–II of abdomen (lateral view, red arrows indicating the median tergites); C. labrum (dorsal view); D. labium (ventral view); E. hypopharynx (ventral view); F. right mandible; G. left mandible; H. left mandible enlarged; I. right mandible enlarged; J. maxilla. Scale bars=1 mm.

FIGURE 16. Imagines of Ephemera cornea sp. nov. A–C: male: A. dorsal view; B. ventral view; C. lateral view; D–F: female: D. dorsal view; E. ventral view; F. lateral view.

FIGURE 17. Male imagines of Ephemera cornea sp. nov. A. foreleg; B. midleg; C. hindleg; D. forewing; E.A1 area of forewing enlarged; F. hindwing; G. abdominal segments I–II (red arrow indicating the median spine on tergite II); H–K: genitalia: H. dorsal view; I. ventral view; J. lateral view; K. apex of left penis enlarged (lateral view).

FIGURE 19. Nymphs of Ephemera japonica. A. male (dorsal view); B. male (ventral view); C. female (dorsal view); D. female (ventral view).

FIGURE 20. Imagines of Ephemera japonica. A–E. female: A. dorsal view; B. ventral view; C. lateral view; D. forewing; E. hindwing; F. male genitalia (dorsal view).

FIGURE 22. Nymphs of Ephemera obliqua sp. nov. A. head and prothorax (dorsal view); B. abdominal segments I–II (lateral view, arrows indicating the tergal spines); C. gill II; D. gill I. Scale bars=1.0 mm.

FIGURE 24. Imagines of Ephemera obliqua sp. nov. A–C: Male imagine:A. lateral view; B. dorsal view; C. ventral view; D–F: female imagine: D. lateral view; E. dorsal view; F. ventral view.

FIGURE 25. Imagines of Ephemera obliqua sp. nov. A. forewing of female; B. A1 area of male forewing enlarged; C. tergites I–II of female (lateral view, red arrow indicating the median spine on tergite II); D. tergites I–II of male (lateral view, red arrow indicating the median spine on tergite II); E. hindwing of female; F. male genitalia (ventral view); G. apex of penes enlarged. Scale bars=1.0 mm.

FIGURE 27. Nymphs of Ephemera pictipennis. A. male (dorsal view); B. male (ventral view); C. female (dorsal view); D. female (ventral view).

FIGURE 29. Imagines of Ephemera pictipennis. A–C: male: A. dorsal view; B. ventral view; C. lateral view; D–F: female: D. dorsal view; E. ventral view; F. lateral view.

FIGURE 30. Male imagine of Ephemera pictipennis. A. foreleg; B. midleg; C. hindleg; D. forewing; E. hindwing; F. A1 area of forewing enlarged; G. genitalia (ventral view); H. apex of right penis enlarged (ventral view).

FIGURE 31. Female imagines of Ephemera pictipennis. A. foreleg; B. midleg; C. hindleg; D. forewing; E. hindwing.

FIGURE 33. Nymphs of Ephemera pictiventris. A. female (dorsal view); B. female (ventral view); C. male (dorsal view); D. male (ventral view).

FIGURE 34. Nymphs of Ephemera pictiventris. A. head and pronotum (dorsal view); B. tergites I–II (lateral view, red arrows indicating the median ridges of tergites I and II).

FIGURE 35. Imagines of Ephemera pictiventris. A. male (lateral view); B. female (lateral view).

FIGURE 36. Imagines of Ephemera pictiventris. A. male (dorsal view); B. male (ventral view); C. female (dorsal view); D. female (ventral view).

FIGURE 37. Male imagines of Ephemera pictiventris. A. foreleg; B. midleg; C. hindleg; D. tergites I–II (arrow indicating the spine of tergite II); E. forewing; F. A1 area of forewing enlarged; G. hindwing; H. genitalia (dorsal view); I. apex of left penis enlarged.

FIGURE 39. Nymphs of Ephemera purpurata. A. male (dorsal view); B. male (ventral view); C. female (dorsal view); D. female (ventral view).

FIGURE 40. Nymphs of Ephemera purpurata. A. head and pronotum (dorsal view); B. tergites I–II (lateral view, red arrows indicating the median tergites I and II); C. foreleg; D. midleg; E. hindleg; F. gill I; G. gill II.

FIGURE 42. Imaginal morphology of Ephemera purpurata. A.male (lateral view); B. female (lateral view); C. tergites I–II of male (lateral view, red arrows indicating the median tergites I and II); D. male genitalia (ventral view); E. forewing of male; F. hindwing of male; G. A1 area of forwing enlarged; H. apex of left penis enlarged (ventral view).

FIGURE 43. Imagines of Ephemera purpurata. A. male (dorsal view); B. male (ventral view); C. female (dorsal view); D. female (ventral view).

FIGURE 45. Nymphs of Ephemera rubera sp. nov. A. dorsal view; B. ventral view; C. anterior part of body (dorsal view); D. tergites I–II (lateral view, red arrow indicating the median ridge on tergites I).

FIGURE 46. Male imagine of Ephemera rubera sp. nov. A. dorsal view; B. lateral view; C. ventral view.

FIGURE 47. Male imagine of Ephemera rubera sp. nov. A. forewing; B. hindwing; C. base of forewing; D. tergites I–II (lateral view, red arrows indicating the median tergites I and II); E. genitalia (ventral view); F. apex of penes enlarged (ventral view).

FIGURE 48. Nymphs of Ephemera rubrogata sp. nov. A. dorsal view; B. ventral view.

FIGURE 51. Imagines of Ephemera rubrogata sp. nov. A. male (lateral view); B. female (lateral view).

FIGURE 52. Imagines of Ephemera rubrogata sp. nov. A. male (dorsal view); B. male (ventral view); C. female (dorsal view); D. female (ventral view).

FIGURE 53. Male imagine of Ephemera rubrogata sp. nov. A. forewing; B. base of forewing; C. hindwing; D. tergites I–II (lateral view, red arrows indicating the median spines on tergites I and II); E. genitalia (ventral view); F. genitalia (dorsal view); G. apex of left penis enlarged (ventral view).

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

FIGURE 56. Imagines of Ephemera shengmi. A. male (lateral view); B. female (lateral view).

FIGURE 57. Imagines of Ephemera shengmi. A. male (dorsal view); B. male (ventral view); C. female (dorsal view); D. female (ventral view).

FIGURE 58. Male imagines of Ephemera shengmi. A. foreleg; B. midleg; C. hindleg; D. forewing; E. abdominal segments I–II (lateral view, red arrows indicating the median tergites I and II); F. hindwing; G. genitalia (dorsal view); H. genitalia (ventral view); I. penes enlarged (dorsal view).

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

FIGURE 61. Nymphal morphology of Ephemera strigata. A. head and pronotum (dorsal view); B. abdominal segments I–II (lateral view, red arrows indicating the median tergites I and II).

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 63. Morphology of European species Ephemera glaucops. A. dorsal view of nymph; B. abdomen of male imago (dorsal view); C. 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.