Scopula species

Makhov, Ilya, 2023, Geometridae (Lepidoptera) of the Baikal region: identification keys and annotated catalogue with notes to DNA barcoding. Part 2. Archiearinae, Geometrinae, Sterrhinae, Zootaxa 5294 (1), pp. 1-120 : 21-24

Key to Scopula species of the Baikal region

Identification key to Scopula species given below partly duplicates the key provided by Viidalepp (2005). However, the present key also includes females.

1. Antenna distinctly chequered with white and dark brown. Forewing with 4–5 wide ochreous brown transverse lines ( Fig. 23C ). In male genitalia ( Figs. 42M–42O ) vesica with two cornuti, left ceras significantly shorter than right one; in female genitalia ( Fig. 51G ) sterigma with wide lamella antevaginalis and semicircular clasp around ostium, signum developed as whole drop-shaped laterally spinulose plate.................................................. S. immorata (Linnaeus, 1758)

- Antenna not chequered................................................................................. 2

2. Frons white.......................................................................................... 3

- Frons black or dark brown.............................................................................. 4

3. Forewing with distinct dark dentate postmedial line which bordered along the entire length by broad dark spots ( Fig. 29A ). In male genitalia sacculus strongly sclerotized and pointed, socii almost as long as sacculus; phallos narrow; right ceras longer than left one ( Figs. 47M–47P ). In female genitalia lamella antevaginalis without round sclerites, corpus bursae without signum ( Fig. 54G )............................................................... S. aequifasciata (Christoph, 1881)

- Forewing without distinct dark postmedial line and broad dark spots ( Fig. 24C ). In male genitalia sacculus moderately sclerotized, not pointed, socii shorter than sacculus; phallos robust; left ceras longer than right one ( Figs. 43K–43M ). In female genitalia ( Fig. 52D ) lamella antevaginalis anteriorly with two separate round sclerites, corpus bursae with signum..................................................................................... S. nemoraria (Hübner, 1799)

4. Ground colour of wings clear white, postmedial line narrow, contrast (almost black), terminal area of both wings with brown and/or blue-gray spots................................................................................. 5

- Wing pattern different.................................................................................. 6

5. Postmedial line of hindwing distally bordered by dark ochreous spots between M1 and M3 and in tornal area ( Fig. 25C ). In male genitalia ( Figs. 45A–45C ) fibula tapering, cerata near equal in length. In female genitalia ( Fig. 53B ) lamella antevaginalis with V-shaped central fold, signum developed as numerous small spinules........................ S. ornata (Scopoli, 1763)

- Postmedial line of hindwing distally bordered by bluish spots between M1 and M3 and in tornal area ( Fig. 25D ). In male genitalia ( Figs. 45D–45F ) fibula rounded apically, left ceras shortened. In female genitalia ( Fig. 53C ) lamella antevaginalis without V-shaped central fold, signum not developed, corpus bursae medially only with granulated surface.............................................................................. S. decorata ([Denis & Schiffermüller], 1775)

6. Males.............................................................................................. 7

- Females............................................................................................ 29

7. Hindtibia with well-developed apical spurs ( Fig. 6E )......................................................... 8

- Hindtibia without apical spurs or they reduced............................................................. 10

8. Forewing length does not exceed 9 mm, its terminal area conspicuously darker than rest part of wing ( Fig. 26C ); fibula sclerotized not stronger than valvula, both cerata normally developed, near same length ( Figs. 45N, 45O )........................................................................................... S. impersonata (Walker, 1861)

- Forewing length more than 10 mm; fibula sclerotized clearly stronger than valvula, one or both cerata commonly shortened.. ................................................................................................... 9

9. Antennal cilia comparatively long: 1.5–1.65 times width of flagellum, frons, vertex and collar light brown mixed with blackish scales; hindwing with distinct discal spot ( Fig. 29B ); both cerata very short and barely sclerotized, anterior margin of sternite A8 concave; vesica with elongate sclerite ( Figs. 48B, 48C )................................ S. cajanderi (Herz, 1904)

- Antennal cilia comparatively short: 1–1.3 times width of flagellum, frons black, vertex and collar sand coloured; hindwing without discal spot ( Fig. 27D ); sternite A8 usually with long right and short left cerata, anterior margin of sternite A8 convex; vesica without sclerite ( Figs. 46M, 46N, 46P )........................................... S. ternata Schrank, 1802

10. Hindleg: tarsus longer than tibia ( Fig. 6F ).......................................... S. rubiginata (Hufnagel, 1767)

- Hindleg: tarsus shorter than tibia or nearly as long ( Fig. 6G–6J )............................................... 11

11. Hind tarsus reduced, 3–4 times shorter than hindtibia ( Figs. 6G, 6H )............................................ 12

- Hind tarsus ½ length of hindtibia or more than ½ length of hindtibia ( Figs. 6I, 6J )................................. 14

12. Genital segment elongate: saccus elliptic, tegumen between socii sclerotized, prominent, reminiscent of uncus; aedeagus without ventrally protruding sclerite at tip ( Figs. 47J, 47K ). Ground colour of wings yellowish white ( Fig. 28D )...................................................................................... S. floslactata (Haworth, 1809)

- Genital segment not elongate: saccus broad and round, tegumen between socii not prominent; aedeagus with ventrally protruding sclerite at tip. Ground colour of wings glossy white......................................................... 13

13. Socii very long, terminally curved and dilated; sternite A8 with both cerata long and symmetrical, protruding beyond posterior margin of mappa, or left ceras shortened and strongly curved ( Figs. 47A, 47B ). Wings with terminal dots, at least at anterior third of forewing ( Fig. 28A )............................................ S. subpunctaria (Herrich-Schäffer, 1847)

- Socii shorter than in S. subpunctaria , terminally straight and not dilated; sternite A8 with both cerata of almost equal length, not curved, cerata not protruding beyond posterior margin of mappa ( Figs. 47D, 47E ). Wings without terminal dots ( Fig. 28B )................................................................................. S. prouti Djakonov, 1935

14. Valvula and fibula sclerotized almost equally or fibula just slightly darker than valvula, fibula commonly with rounded tip; genitalia often asymmetric............................................................................. 15

- Fibula strongly sclerotized, significantly darker than valvula, often pointed; genitalia commonly symmetric............ 21

15. Hindleg: tarsus longer than 1/2 length of tibia, reaches about 2/3–3/4 length of tibia, occasionally almost equal to tibia ( Fig. 6I )................................................................................................ 16

- Hindleg: length of tarsus near 1/2 length of tibia ( Fig. 6J ).................................................... 19

16. Both fibulae bifid.................................................................................... 17

- If fibula bifid, than only on the one side.................................................................. 18

17. Fibula with two separate curved projections, aedeagus curved, vesica with two elongate cornuti; right ceras long and strongly curved, left ceras short, broad, strongly spinose ( Figs. 44H–44K ). Forewing without discal spot ( Fig. 25B ).............................................................................. S. virgulata ([Denis & Schiffermüller], 1775)

- Fibulae asymmetrically bifurcated only in apical parts, vesica with one strongly curved dentate cornutus; cerata near same length ( Figs. 42J–42L ). Forewing with discal spot ( Fig. 23B ).......................... S. agutsaensis Vasilenko, 1997

18. Length of socii near equal to distance between outer margins of their bases, right ceras longer than left one ( Figs. 43G, 43H ); forewing with discal and terminal dots ( Fig. 24B )....................................... S. dignata (Guenée, 1858)

- Length of socii does not exceed ½ distance between outer margins of their bases, right ceras no longer than left one ( Figs. 43D, 43E ); forewing without discal and terminal dots (rarely forewing with weak discal dot) ( Fig. 24A ).................................................................................................. S. virginalis (Fourcroy, 1785)

19. Genital segment symmetric, fibula and valvula tapering; both cerata short, strongly spinose ( Figs. 43A, 43B ).................................................................................... S. corrivalaria (Kretschmar, 1862)

- Genital segment clearly asymmetric: right and left fibulae of different structure; cerata of different lengths, at least one ceras rather long: protruding beyond posterior margin of mappa.................................................... 20

20. Right fibula flat, bilobed, both valvulae strongly curved at tips; vesica with large terminally rounded sclerites; left ceras very short, right ceras long and thin ( Figs. 44E–44G ).................................. S. nigropunctata (Hufnagel, 1767)

- Right fibula furcate, pincer-shaped; vesica with 3–4 terminal sclerites, one of them claw-shaped: long, curved and tapered; sternite A8 with both cerata long and narrow ( Figs. 44A–44D ).......................... S. umbelaria (Hübner, 1813)

21. Cerata almost equal in length, short, not reaching posterior margin of VIII sternite................................. 22

- One or both cerata reaching posterior margin of sternite A8, or longer and protruding beyond posterior margin of sternite A8................................................................................................... 25

22. Anterior margin of sternite A8 concave medially, tips of cerata not spinose ( Figs. 48D, 48E ); wing pale sand coloured, transverse lines contrast, brown, fine, more or less straight, parallel to each other ( Fig. 29C )........................................................................................................ S. albiceraria (Herrich-Schäffer, 1844)

- Anterior margin of sternite A8 convex medially, cerata with spinose tips (sometimes barely spinose); wing pattern different.. .................................................................................................. 23

23. Phallos almost straight, coecum of aedeagus not bent ventrally ( Fig. 46L ); ground colour of wings dark gray brown, discal spots and terminal dots absent ( Fig. 27C )............................................... S. frigidaria (Möschler, 1860)

- Phallos arched: apex and coecum of aedeagus slightly bent ventrally; ground colour of wings different, discal spots or/and terminal dots present.................................................................................. 24

24. Sternite A8 with constriction in middle part, cerata very short, slightly curved ( Figs. 6A , 46B ); wings sand-coloured, with light brown tinge; terminal dots present, elongate; forewing apex pointed, forewing postmedial line dark brown, often discontinuous ( Fig. 26D ).................................................................... S. beckeraria (Lederer, 1853)

- Sternite A8 rounded, with cerata strongly curved ( Fig. 6D ); ground colour of wings white with yellow suffusion, terminal dots absent or very small and pale; forewing apex not pointed, forewing postmedial line yellowish, usually continuous ( Fig. 27B )................................................. S. immutata (Linnaeus, 1758) (rare form with both short cerata)

25. Left fibula markedly smaller than right one ( Fig. 47G ); hindwing termen clearly angled: wing shortly tailed at M3 ( Fig. 28C ).............................................................................. S. flaccidaria (Zeller, 1852)

- Both fibulae about same size; hindwing termen rather smooth, wing not tailed at M3 ............................... 26

26. Both cerata of equal length: long, protruding beyond posterior margin of mappa ( Fig. 46E ).... S. incanata (Linnaeus, 1758)

- Cerata of unequal length, only one of them protruding beyond posterior margin of mappa........................... 27

27. Postmedial line of forewing (often also of hindwing) distally bordered by wide, contrast, dark gray fascia (occasionally discontinuous); ground colour of wings reddish brown (in fresh samples) to grayish ochreous ( Fig. 26A ); sternite A8 elongate (its length is about twice its width), left ceras very short: about 5 times shorter than right one ( Fig. 45I )........................................................................................... S. permutata (Staudinger, 1897)

- Wings without wide, contrast, dark gray fascia distal of postmedial line; sternite A8 different........................ 28

28. Sternite A8 with constriction in middle part; cerata slightly curved, right ceras slightly longer than left one ( Fig. 6B ); for external differences see point 24 .................................... S. beckeraria (rare form with both long cerata)

- Sternite A8 without constriction in middle part, cerata strongly curved, right ceras 3–4 times longer than left one, semicircular ( Figs. 6C , 46H ); for external differences see point 24 ................................................ S. immutata

29. Corpus bursae drop-shaped, its posterior part (1/3 to 1/2) strongly sclerotized, ductus bursae extremely short, signum consists of few tiny sclerites (near 10) ( Fig. 53A ).......................................................... S. virgulata

- Genitalia different................................................................................... 30

30. Ductus bursae broad, with lateral longitudinal sclerotization ( Fig. 52A )............................... S. corrivalaria

- Ductus bursae different................................................................................ 31

31. Ductus bursae very short and broad, posterior parts of corpus bursae with granulated surface opposite signum patch ( Fig. 51F ).................................................................................... S. agutsaensis

- Ductus bursae commonly narrow and moderately long or short and broad; posterior parts of corpus bursae without granulated surface opposite signum patch.......................................................................... 32

32. Ostium broad (as broad as ½ width of posterior margin of tergite A8 or broader), well sclerotized ( Figs. 52B , 53E, 53F )... 33

- Genitalia different................................................................................... 35

33. Lamella antevaginalis not developed; ostium opened, funnel-shaped (tapered anteriorly), attached to narrow antrum...... 34

- Ostium not funnel-shaped, lamella antevaginalis well developed: wide, near oval, covers ostium ( Fig. 52B )..... S. virginalis

34. Wings brown, light brown or rosy brown, discal spot of forewing very small, often indistinct ( Fig. 26B ); ductus bursae longer than in S. impersonata , signum well developed: numerous spinules form oval or drop-shaped patch ( Fig. 53E )..................................................................................................... S. rubiginata

- Wings different shades of gray, discal spot of forewing well pronounced ( Fig. 26C ); ductus bursae shorter than in S. rubiginata , signum weakly developed: few spinules unevenly scattered around narrow (often broken) longitudinal sclerite ( Fig. 53F )............................................................................................ S. impersonata

35. Signum absent...................................................................................... 36

- Signum present...................................................................................... 37

36. Wings pale yellow, transverse lines yellowish brown ( Fig. 29C ); lamella antevaginalis rather slender, crescent-shaped, ductus bursae comparatively narrow and long ( Fig. 55C ).................................................. S. albiceraria

- Wings pale gray (rarely with yellowish tinge) with dark gray transverse lines ( Fig. 29B ); lamella antevaginalis larger and wider than in S. albiceraria , ductus bursae shorter and broader than in S. albiceraria ( Fig. 55B )................... S. cajanderi

37. Ostium near symmetric, commonly with semicircular or circular structures ( Figs. 52C , 53D, 53G, 53H , 54A–54F , 55A )... 39

- Ostium asymmetric, without semicircular or circular structures, consists of several irregular sclerites ( Figs. 52E, 52F ).... 38

38. Wings with sharp discal spots and usually with almost continuous terminal lines, fringe of forewing without dark dots ( Fig. 25A ); lamella antevaginalis with distinct, irregular folds ( Fig. 52F )................................. S. nigropunctata

- Discal spots commonly absent, terminal lines fine, discontinuous, usually broken into short and weak dashes or dots, fringe of forewing with dark dots ( Fig. 24D ); lamella antevaginalis with large lateral (left) sclerite ( Fig. 52E )........... S. umbelaria

39. Postmedial line of forewing distinct, zigzagging, distally bordered by wide, contrast, dark gray fascia (occasionally discontinuous); ground colour of wings reddish brown (in fresh samples) to grayish ochreous ( Fig. 26A ); genitalia: Fig. 53D........................................................................................... S . permutata

- Wing pattern different................................................................................. 40

40. Corpus bursae near round, barely elongated; signum near ductus bursae, very small, not elongated, of undefined shape, spinules very small ( Fig. 54F )........................................................................ S. floslactata

- Corpus bursae more or less elongated, signum rather large, oval or elongated, usually located in central part of corpus bursae .................................................................................................. 41

41. Lamella postvaginalis well developed, lamella antevaginalis and lamella postvaginalis flat (without folds or bulging), forming transverse cleft, in center of which ostium is located ( Fig. 52C ).......................................... S. dignata

- Lamella postvaginalis not developed, ostium usually surrounded by semicircular or ring-shaped lamella antevaginalis.... 42

42. Ground colour glossy white, transverse lines yellowish gray; postmedial line of forewing sharply bent inwards near costa, forming right or acute angle ( Figs. 28A, 28B ); lamella antevaginalis posteriorly and laterally strongly sclerotized, anteriorly weakly sclerotized, not swollen, without transverse fold ( Figs. 54D, 54E )........................................ 43

- Ground colour different or postmedial line of forewing not bent inwards near costa; lamella antevaginalis commonly anteriorly strongly sclerotized, or swollen, or with transverse fold...................................................... 44

43. Lamella antevaginalis rather round; signum with distinct longitudinal medial ridge of fused spinules ( Fig. 54D ).................................................................................................. S. subpunctaria

- Lamella antevaginalis rather elongated, its anterior end markedly oblique relatively posterior end; fused spinules of signum does not form more or less continuous longitudinal medial ridge but usually forms few groups along medial axis ( Fig. 54E ).............................................................................................. S. prouti

44. Sterigma with two lateral longitudinal sclerotized folds, signum very slender, spinules often fused to medial ridge ( Fig. 54A ).......................................................................................... S. immutata

- Sterigma different: without lateral longitudinal sclerotized folds, signum more oval................................ 45

45. Hindwing termen clearly angled: wing shortly tailed at M3, tornus almost right angled ( Fig. 28C ); genitalia: Fig. 55A................................................................................................ S . flaccidaria

- Hindwing rounded, termen rather smooth................................................................. 46

46. Wings without discal spots (in rare cases discal dot very weak, not darker than medial line) and without terminal dots, forewing apex not pointed..................................................................................... 47

- Wings with distinct discal spots (they always darker than medial line) and distinct terminal dots, forewing apex slightly pointed............................................................................................ 48

47. Lamella antevaginalis semicircular, slightly swollen anteriorly ( Fig. 54C ).................................. S. ternata

- Lamella antevaginalis oval, not swollen anteriorly ( Fig. 54B )......................................... S. frigidaria

48. Lamella antevaginalis with swollen C-shaped pad ( Fig. 53H ); ground colour of wings gray to pale gray ( Fig. 27A ).................................................................................................... S. incanata

- Lamella antevaginalis with strongly sclerotized transverse fold ( Fig. 53G ); wings sand coloured, with light brown tinge ( Fig. 26D )..................................................................................... S. beckeraria

Figures

FIGURE 6. Structure details of Scopula males. A–D—polymorphism of sternite A8 in some species; E–J—distal part of hindleg (tibia and tarsus).A, B—S. beckeraria; C, D—S. immutata; E—S. cajanderi; F—S. rubiginata; G—S. floslactata; H—S. subpunctaria; I—S. virgulata; J—S. corrivalaria.

FIGURE 23. Adults of Siberian Sterrhinae. A—Holarctias rufinularia; B—Scopula agutsaensis; C—S. immorata; D—S. corrivalaria.

FIGURE 24. Adults of Siberian Sterrhinae. A—Scopula virginalis; B—S. dignata; C—S. nemoraria; D—S. umbelaria.

FIGURE 25. Adults of Siberian Sterrhinae. A—Scopula nigropunctata; B—S. virgulata; C—S. ornata; D—S. decorata.

FIGURE 26. Adults of Siberian Sterrhinae. A—Scopula permutata; B—S. rubiginata; C—S. impersonata; D—S. beckeraria.

FIGURE 27. Adults of Siberian Sterrhinae. A—Scopula incanata; B—S. immutata; C—S. frigidaria; D—S. ternata.

FIGURE 28. Adults of Siberian Sterrhinae. A—Scopula subpunctaria; B—S. prouti; C—S. flaccidaria; D—S. floslactata.

FIGURE 29. Adults of Siberian Sterrhinae. A—Scopula aequifasciata; B—S. cajanderi; C—S. albiceraria; D—Cyclophora albipunctata.

FIGURE 42. Male genitalia of Siberian Sterrhinae. A–C—Idaea descitaria; D–F—Holarctias rufinaria; G–I—H. rufinularia; J–L—Scopula agutsaensis; M–O—S. immorata. A, E, I, L, N—genital segment, ventral view; B—ditto, valvae shifted; C, D, H, K, O—phallos; G, F, J, M—sternite A8. Scale bar—1 mm.

FIGURE 43. Male genitalia of Siberian Sterrhinae.A–C—Scopula corrivalaria; D–F—S. virginalis; G–J—S. dignata; K–M— S. nemoraria. A, E, G, K—genital segment; B, D, H, M—sternite A8; C, F, I, L—phallos; J—ditto, vesica everted. Scale bar—1 mm.

FIGURE 44. Male genitalia of Siberian Sterrhinae.A–D—Scopula umbelaria; E–G—S. nigropunctata; H–K—S. virgulata. A, E, H, K—genital segment; B, G, J—phallos; C, D, F, I—sternite A8. Scale bar—1 mm.

FIGURE 45. Male genitalia of Siberian Sterrhinae. A–C—Scopula ornata; D–F—S. decorata; G–I—S. permutata; J–L—S. rubiginata; M–O—S. impersonata. A, E, G, K, N—genital segment; B, D, I, J, O—sternite A8; C, F, H, L, M—phallos. Scale bar—1 mm.

FIGURE 46. Male genitalia of Siberian Sterrhinae.A–C—Scopula beckeraria; D–F—S. incanata; G–I—S. immutata; J–L—S. frigidaria; M–P—S. ternata. A, D, G, K, O—genital segment; B, E, H, J, M, P—sternite A8; C, F, I, L, N—phallos. Scale bar—1 mm.

FIGURE 47. Male genitalia of Siberian Sterrhinae. A–C—Scopula subpunctaria; D–F—S. prouti; G–I—S. flaccidaria; J–L— S. floslactata; M–P—S. aequifasciata. A, D, G, J, P—genital segment; B, E, H, L, O—sternite A8; C, F, I, K, M, N—phallos (M—lateral view, N—ventral view). Scale bar—1 mm.

FIGURE 48. Male genitalia of Siberian Sterrhinae. A–C—Scopula cajanderi; D–G—S. albiceraria; H, I—Cyclophora albipunctata; J, K—Timandra rectistrigaria; L–N—T. griseata. A, F—genital segment; H, J, L, N—genital segment; B, D, E—sternite A8; C, G, I, K, M—phallos. Scale bar—1 mm.

FIGURE 51. Female genitalia of Siberian Sterrhinae. A—Idaea straminata; B—I. dimidiata; C—I. descitaria; D—Holarctias rufinaria; E—H. rufinularia; F—Scopula agutsaensis; G—S. immorata. Scale bar—1 mm.

FIGURE 52. Female genitalia of Siberian Sterrhinae. A—Scopula corrivalaria; B—S. virginalis; C—S. dignata; D—S. nemoraria; E—S. umbelaria; F—S. nigropunctata. Scale bar—1 mm.

FIGURE 53. Female genitalia of Siberian Sterrhinae. A—Scopula virgulata; B—S. ornata; C—S. decorata; D—S. permutata; E—S. rubiginata; F—S. impersonata; G—S. beckeraria; H—S. incanata. Scale bar—1 mm.

FIGURE 54. Female genitalia of Siberian Sterrhinae. A—Scopula immutata; B—S. frigidaria; C—S. ternata; D—S. subpunctaria; E—S. prouti; F—S. floslactata; G—S. aequifasciata. Scale bar—1 mm.

FIGURE 55. Female genitalia of Siberian Sterrhinae. A—Scopula flaccidaria; B—S. cajanderi; C—S. albiceraria; D— Cyclophora albipunctata; E—Timandra rectistrigaria; F—T. griseata. Scale bar—1 mm.