Idaea 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 : 24-26

Key to Idaea species of the Baikal region

1. Wings with purple and yellow portions, and one dark transverse line ( Fig. 20C ); ground colour of both wings is commonly purplish-red with large yellow discal spots and wide yellow terminal stripe. In male genitalia ( Figs. 40N–40P ) uncus bifid, valva without modifications, extremely narrow, widened distally; vesica with small cornutus. In female genitalia ( Fig. 50C ) ductus weakly sclerotized, with longitudinal furrows.................................. I. muricata (Hufnagel, 1767)

- Coloration and pattern of wing different................................................................... 2

2. Ground colour of wings brightly rufous, dark yellow or deep brown with contrasting transverse lines or without them...... 3

- Ground colour of wings pale yellow, grayish or whitish with thin or not contrasting transverse lines.................... 6

3. Wings different shades of rufous or yellow, in male genitalia valva with either process on ventral margin, or narrowed medially; in female genitalia corpus bursae not spherical, or if spherical then only its posterior part covered with tiny spines........ 4

- Wings different shades of brown (in fresh samples deep reddish-brown or brightly ochreous), with slightly sinuous dark transverse lines (2–3 lines on forewing and 2 lines on hindwing). In male genitalia ( Figs. 40H–40J ) valva with straight ventral margin, not narrowed medially; in female genitalia ( Fig. 50A ) ductus sclerotized, corpus bursae spherical, membranous, entirely covered with tiny spines.......................................................... I. falckii (Hedemann, 1879)

4. Wings bright yellow or pale orange, with dark, almost transverse lines (3 lines on forewing and 2 lines on hindwing), fringes blackish; hindwing without discal dot. In male genitalia ( Figs. 40K–40M ) vesica with no cornuti, juxta with pair of long processes, valva simple, without projections on their margins; in female genitalia ( Fig. 50B ) ostium comparatively wide.................................................................. I. aureolaria ([Denis & Schiffermüller], 1775)

- Wings rufous or rusty brown, with not contrasting, often weakly distinct wavy lines; hindwing with discal dot; in male genitalia vesica with cornutus, juxta without processes, ventral margin of valva with projection; in female genitalia ostium comparatively narrow.............................................................................................. 5

5. In male genitalia ( Figs. 40A –0C) valva with small projection on ventral margin; saccus more elongated than in I. serpentata ; cornutus very large, bent at angle of almost 90°, apex of cornutus protrudes beyond apex of aedeagus. In female genitalia ( Fig. 49J ) corpus bursae elongated, more than 2 mm .................................... I. dohlmanni (Hedemann, 1881)

- In male genitalia ( Figs. 40F, 40G ) valva with process on ventral margin; saccus shorter than in I. dohlmanni , rounded; cornutus smaller than in I. dohlmanni , less curved, its apex does not protrude beyond apex of aedeagus. In female genitalia corpus bursae short, its length is about 1 mm ( Fig. 49I )........................................... I. serpentata (Hufnagel, 1767)

6. In male genitalia phallos extremely long: more than 5 mm, coiled, vesica with more than 20 thorn-shaped cornuti and long filiform sclerite ( Figs. 41L, 41M ); in female genitalia ductus seminalis very long, coiled, with numerous sclerotized spicules ( Fig. 51A )................................................................ I. straminata (Borkhausen, 1794)

- In male genitalia phallos considerably shorter than 5 mm, number of cornuti varies from 1 to 3; in female genitalia ductus seminalis not coiled................................................................................... 7

7. Males.............................................................................................. 8

- Females............................................................................................ 13

7. Costal margin of valva with dentiform projection in distal half.................................................. 8

- Costal margin of valva without processes.................................................................. 9

8. Apex of aedeagus with pair of horn-like sclerotized appendages; saccus comparatively wide; valva narrowed distally, with sharp notch distad of costal projection ( Figs. 41F, 41G )........................... I. nitidata (Herrich-Schäffer, 1861)

- Apex of aedeagus without horn-like appendages, vesica with one hook-shaped cornutus; saccus narrow; valva gradually narrowed toward tip, without sharp notch distad of costal projection ( Figs. 41C–41E )............................................................................................... I. pallidata ([Denis & Schiffermüller], 1775)

9. Valvae distinctly asymmetric, right one with more elongated and bent apex; aedeagus curved, S-shaped ( Figs. 39M, 39N ); terminal area of forewing often with 3–4 distinct dark brown spots near tornus.............. I. dimidiata (Hufnagel, 1767)

- Valvae symmetrical, their apices not elongated and not bent; aedeagus relatively straight, occasionally with dorsally bent coecum............................................................................................ 10

10. Vesica with 1 spiniform or rod-shaped or laminiform cornutus, or latter is absent; tegumen without sclerotized dentate processes under uncus......................................................................................... 11

- Vesica with 3 or more cornuti; tegumen with pair strongly sclerotized dentate processes under uncus ( Figs. 41J, 41K ).................................................................................... I. aversata (Linnaeus, 1758)

11. Valva tapered distally; vesica with straight long cornutus ( Figs. 42A–42C ); wings dark gray ( Fig. 22C )............................................................................................. I. descitaria (Christoph, 1893)

- Valva almost not tapered distally, its apex roundish; cornutus different; wings not gray: pale yellow to grayish-ochreous... 12

12. Valva with 3–5 small strongly sclerotized spines on inner surface near ventral margin and apex; vesica with robust, S-shaped cornutus; coecum of aedeagus bent dorsally ( Figs. 41H, 41I )............................. I. biselata (Hufnagel, 1767)

- Valva without small sclerotized spines on its inner surface; vesica bears thin broad irregular plate with more sclerotized lateral edges; coecum of aedeagus not bent dorsally ( Figs. 41A, 41B ).......................... I. sylvestraria (Hübner, 1799)

13. Anterior part of corpus bursae with membranous appendix ( Fig. 50D ).................................. I. sylvestraria

- Anterior part of corpus bursae without appendix............................................................ 14

14. Ductus bursae with spherical membranous appendix ( Fig. 50G ).......................................... I. biselata

- Ductus bursae without spherical membranous appendix...................................................... 15

15. Posterior part of corpus bursae twisted; ductus bursae narrow and long, well sclerotized ( Fig. 50H )............ I. aversata

- Posterior part of corpus bursae not twisted................................................................ 16

16. Posterior part of ductus bursae with broad sclerotized plate near ostium ( Fig. 50F ); signa fill only anterior part of corpus bursae, also forming separate narrow strip of spines in central part of corpus bursae................................ I. nitidata

- Posterior part of ductus bursae without broad sclerotized plate near ostium; signa fill almost all inner surface of corpus bursae or one of its lateral side............................................................................... 17

17. Corpus bursae elongated, one of its lateral side or / and its anterior end membranous, without signa ( Fig. 51C ); ductus seminalis arises from posterior part of corpus bursae; ductus bursae rather uniformly sclerotized; wings dark gray........ I. descitaria

- Corpus bursae more or less spherical, entirely filled with signa; ductus seminalis different; ductus bursae sclerotized nonuniformly: just its posterior part or only central (lateral sides of ductus bursae membranous); coloration of wings different .................................................................................................. 18

18. Ductus bursae rather broad, with longitudinal sclerotization in central part, its posterior part without spines ( Fig. 50E ); ductus seminalis arises from large membranous appendix in posterior part of corpus bursae........................ I. pallidata

- Ductus bursae narrow, almost entirely membranous, only its posterior part filled with tiny thin spines ( Fig. 51B ); corpus bursae without appendix in posterior part; terminal area of forewing often with 3–4 distinct dark brown spots near tornus.................................................................................................... I. dimidiata

Key to Timandra species of the Baikal region

1. Forewing without apical streak; medial line of both wings pale brownish grey; wings with strong brown or grey brown suffusion, wing pattern and discal spots very diffuse; frons strongly convex. In male genitalia ( Figs. 48J, 48K ) costa not furcate, valva with broad ventral subterminal projection; apex of aedeagus straight, without process. In female genitalia antrum T-shaped, with strongly sclerotized lateral projections ( Fig. 55E )................................ T. rectistrigaria ( Eversmann, 1851)

- Forewing with reddish apical streak usually merging into more oblique medial line; wing pattern more distinct, often contrasted; medial line of both wings reddish, rose or brownish grey; frons more or less protruded. In male genitalia sclerites of valva partially cleft, costa furcate; apex of aedeagus curved or with process. In female genitalia antrum different.............. 2

2. Frons strongly protruded. In male genitalia ( Figs. 49C, 49D ) margins of socii not spinose; costa of valva with ventro-anally directed finger-like process; sacculus long: more than ¾ of length of costa; apex of aedeagus curved, without process. In female genitalia ( Fig. 56B ) ostium with large trapezoid sclerite covered with stout scales............... T. paralias (Prout, 1935)

- Frons slightly protruded. In male genitalia costa of valva with dorsally directed process; sacculus short (about ½ of length of costa), sub-triangular, with long narrow sclerotized process; in female genitalia ductus bursae comparatively broad, mostly sclerotized........................................................................................... 3

3. Ground colour of wings whitish or greyish with dense dark-grey dusting; oblique medial line usually weak and thin ( Fig. 30B ). In male genitalia ( Figs. 48L–48N ) socii shallowly wrinkled, with short teeth; in female genitalia posterior margin of sternite A8 straight or slightly concave, appendix bursae angle towards corpus bursae about 120° ( Fig. 55F )................................................................................................... T. griseata W.Petersen, 1902

- Ground colour of wings yellowish, with weak rose tinge especially pronounced outward from medial line; dusting sparse, pale yellowish brown; oblique medial line usually wider, more distinct than in T. griseata ( Fig. 30C ). In male genitalia ( Figs. 49A, 49B ) socii deeply dentate; in female genitalia posterior margin of sternite A8 strongly concave, appendix bursae angle towards corpus bursae about 100° ( Fig. 56A ).................................................. T. recompta (Prout, 1930)

Figures

FIGURE 20. Adults of Siberian Sterrhinae. A—Idaea falckii; B—I. aureolaria; C—I. muricata; D—I. sylvestraria.

FIGURE 22. Adults of Siberian Sterrhinae. A—Idaea aversata; B—I. straminata; C—I. descitaria; D—Holarctias rufinaria.

FIGURE 30. Adults of Siberian Sterrhinae. A—Timandra rectistrigaria; B—T. griseata; C—T. recompta; D—T. paralias.

FIGURE 39. Male genitalia of Siberian Sterrhinae.A–C—Rhodostrophia jacularia; D–F—R. vibicaria; G–L—Cleta jacutica; M, N—Idaea dimidiata. A, G–K—genital segment; B, F, H, J, L, M—phallos; C, D—sternite A8; E, N—genital segment, valvae shifted. Scale bar—1 mm.

FIGURE 40. Male genitalia of Siberian Sterrhinae.A–C—Idaea dohlmanni; D, E—possible hybrid I. dohlmanni × I.serpentata; F, G—I. serpentata; H–J—I. falckii; K–M—I. aureolaria; N–P—I. muricata. A, D, F, H, K, O—genital segment, ventral view; B, D, I, M, P—ditto, lateral view; C, E, G, J, L, N—phallos. Scale bar—1 mm.

FIGURE 41. Male genitalia of Siberian Sterrhinae. A, B—Idaea sylvestraria; C–E—I. pallidata; F, G—I. nitidata; H, I—I. biselata; J, K—I. aversata; L, M—I. straminata. A, C—genital segment, lateral view; D—ditto, ventral view, valvae shifted; F, H, J, L—ditto, ventral view; B, E, G, I, K, M—phallos. Scale bar—1 mm.

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 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 49. Genitalia of Siberian Sterrhinae. A, B—Timandra recompta; C, D—T. paralias; E, F—Lythria purpuraria; G— Rhodostrophia vibicaria; H—R. jacularia; I—Idaea serpentata; J—I. dohlmanni. A, D, E—genital segment; B, C, F—phallos; G–J—bursa copulatrix of female. Scale bar—1 mm.

FIGURE 50. Female genitalia of Siberian Sterrhinae. A—Idaea falckii; B—I. aureolaria; C—I. muricata; D—I. sylvestraria; E—I. pallidata; F—I. nitidata; G—I. biselata; H—I. aversata. 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 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.

FIGURE 56. Female genitalia of Siberian Sterrhinae. A—Timandra recompta; B—T. paralias; C—Lythria purpuraria. Scale bar—1 mm.