Rhodostrophia tristrigalis Butler, 1889

Kumari, Shabnam, Bandyopadhyay, Uttaran, Uniyal, Virendra Prasad, Chandra, Kailash & Hausmann, Axel, 2024, Integrative taxonomic review of the genus Rhodostrophia Hübner, 1823 and its allied genus Tanaotrichia Warren, 1893 (Lepidoptera: Geometridae) from the Western Himalaya, Zootaxa 5519 (1), pp. 59-89 : 74-77

Rhodostrophia tristrigalis Butler, 1889

[ Fig. 23–26 , 39, 47 , 53, 60 ]

[TL: Dharmsala (Himachal Pradesh), North Western India, India]

Rhodostrophia tristrigalis Butler, 1889 , Illustration Typical Specimens Lepidoptera Heterocera Collection British Museum, 7: 22, 110, pl. 137, fig. 1.

Rhodostrophia tristrigalis ; Hampson, 1895; The Fauna of British India, including Ceylon and Burma, 3: 456.

Rhodostrophia tristrigalis ; Prout, 1913; In: Seitz, A. (Ed.) (1912–1916): The Macrolepidoptera of the world, 4: 42, pl. 3, fig. e.

Rhodostrophia tristrigalis ; Prout, 1938; In: Seitz, A. (Ed.) (1920–1941): The Macrolepidoptera of the world, 12: 144, pl. 15, fig. c.

Rhodostrophia tristrigalis ; Smetacek, 2008; Bionotes, 10 (1): 7.

Material examined: INDIA: 2♀♀, Himachal Pradesh, Dist. Kangra, Dhauladhar Mountain Range, Dhanoti , 32.23183° N, 076.27132° E, 1170 m, 19.X.2019 ; 1♂, 11.X.2020; 2♂♂, 03.IV.2021; 1♂, 02. V.2021; 1♀, 11. V.2022; 1♂, Paroh Bari , 32.21791° N, 076.26783° E, 1018 m, 02.IV.2021 ; 1♀, Nora , 32.26927° N, 076.28972° E, 1455 m, 15.IV.2021 ; 1♂ 3♀♀, Ghera , 32.260173° N, 076.288707° E, 1404 m, 03. V.2021; leg. S. Kumari.

NWR specimes: INDIA: 1♂, Himachal Pradesh, Dist. Kangra, Dhauladhar Mountain Range, Nora , 32.26927° N, 076.28972° E, 1455 m, 08.X.2020 ( BOLD Sample Id: BC_ ZSM _Lep_117631) ; 1♀, Maniyana , 32.2282° N, 076.27434° E, 1118 m, 16.X.2020 ; 1♀, Harnala , 32.28126° N, 076.27037° E, 1796 m, 13.IV.2021; leg. S. Kumari.

Description:

Forewing length: Male: 12–13 mm, Female: 13–15 mm.

Antennae similar to R. stigmatica . Vertex pale ochreous. Frons brown and slightly protruded. Labial palpi short, forwardly directed and hardly reaching the frons, with rose-red irrorations on the lateral sides. Collar, patagia, thorax and abdomen pale ochreous dorsally, and with rose-red irroration on the ventral side; foretibia with rose-red irroration on outer side. Legs features simila to R. pelloniaria except hindtibial hair pencil present and almost reaching the terminal tibial spurs. Forewing pale ochreous, elongated with slightly produced apex, outer margin straight. Antemedial line bent outwardly below the costa till R5, then runs obliquely towards the one-third of the inner margin. Discocellular dot blackish rose-red. Postmedial band continuous, more or less uniformly suffused with rose-red, clearly defined inner edge and diffused outer edge. Submarginal line distinct, rose-red and runs parallel between postmedial band and outer margin. A clear, dark rose-red marginal line. Cilia rose-red with pale ochraceous base and outer edge. Hindwing with the ground colour and markings similar to the forewing except the paler costal margin. Underside with similar markings, dark rose-red irroration especially on veins, inner margins paler; antemedial line absent; discocellular dots black. Cilia darker than upper side ( Figs 23–26 ).

Male genitalia ( Fig. 39 ) Uncus and gnathos similar to R. stigmatica . Valva asymmetric, apical one-fourth narrow, sclerotised, spinulose and bilobed on both sides; right valva with longer, digitate process ventrad, clustered minute setae at the base; left valva with comparatively shorter and blunt ventral digitate process. Costa with small protrusions at the base, strongly curved, separated from the valva, distal dorsal sclerite of valva costa similar to R. stigmatica . Juxta tongue-shaped with narrow central concavity on distal margin. Aedeagus ( Fig. 46 ) long, thin, medially curved followed by a strong subapical turn; terminal part with minute sclerotised dentations. Posterior margin of the 8 th abdominal sternite ( Fig. 53 ) bilobed with wide and shallow central concavity.

Female genitalia ( Fig. 60 ): Papillae anales setose, rounded with a slightly deeper central concavity; posterior apophyses four times the length of the anterior apophyses. Ductus bursae long, sclerotised, strongly bent medially, apically wide with a small protrusion near the antrum; same as the length of corpus bursae. Antrum shallow with strongly sclerotised margin. Corpus bursae ovally-elongated, collar-shaped signum next to the junction with ductus bursae. 7 th sternite sclerotised, posterior margin outwardly curved with two short lateral processes.

Differential diagnosis: Morphologically, R. tristrigalis resembles most closely with R. stigmatica ( Figs 19–22 ) but differs in the course of the transverse lines on wings. R. tristrigalis has transverse lines more oblique (ante and postmedial lines curved in R. stigmatica ), postmedial band with more distinctly defined outer edge (single, distinct postmedial line, sometimes appears to be double with a very faint outer shade in R. stigmatica ); submarginal line obliquely straight (sinuous in latter). Male genitalia of R. tristrigalis have deeper and wider central concavity on the distal apical margin of uncus with comparatively smaller subapical lateral processes than in R. stigmatica ( Fig. 38 ). Costa slightly more curved. Distal apical digitate processes more widely separated, not spinulose on the right valva; the left valva apically bilobed (not in R. stigmatica ). Aedeagus with apical region having minute sclerotised dentations and the posterior margin of the 8 th sternite with shallow but wider central concavity than in R. stigmatica ( Figs 45 , 52 ). Female genitalia is characterised by a broader distal end of dusctus bursae with less acutely curved protrusion, a stronger medial bend without a non-sclerotised portion, and an outcurved posterior margin of the 7 th sternite with small lateral processes.

Remarks: The female genitalia of this species have been described for the first time, with first-ever DNA barcode information. Cui et al. (2019) described two male specimens under the same species name, but their morphological, including both habitus and genitalia characteristics, do not match our specimens. However, the specimens observed in this study were similar to the type specimens ( Figs 24–25 ) of the species.

Distribution: India: Himachal Pradesh (Dharamshala, Sultanpur) ( Prout 1913, 1938), Uttarakhand (Kumaon) (Smetacek 2008). Elsewhere: Shan State (Myanmar, average elevation 1200–1500 m), China (Sichuan, Tibet) ( Hampson 1895; Cui et al. 2019), Bhutan ( Prout 1938).

Genetic data: BIN: BOLD:AAQ0226, 6.43% sequence divergence from the nearest neighbour R. stigmatica .

Bionomics: Adults of R. tristrigalis were recorded within the elevational range of 1000–2200 m, primarily in the Tropical Dry Deciduous (5B/C2) and Subtropical Pine forests (9/C1a, C1b) and with rare sightings in the Himalayan Moist temperate deciduous forest. They were active in both pre- and post-monsoon seasons but were more frequent during the pre-monsoon season. However, the life history and larval stages of this species have not been documented.

Figures

FIGURES 17–28. Habitus images of Rhodostrophia and Tanaotrichia spp. 17. R. pelloniaria (17a–17b: Male, Holotype, NHMUK). 18. R. khasiana (18a–18b: Female, Syntype, NHMUK). 19–22. R. stigmatica (19a–19b: Male, 20a–20b: Female, 21a–21b: Male, Syntype, NHMUK, 22a–22b: Female, Syntype, NHMUK). 23–26. R. tristrigalis (23a–23b: Male, 24a–24b: Female, 25a–25b: Male, Syntype, NHMUK, 26a–26b: Female, Syntype, NHMUK). 27–28. R. vinacearia (27a–27b: Female, 28a–28b: Male, Syntype, NHMUK).

FIGURES 34–47. Male genitalia images of Rhodostrophia and Tanaotrichia spp. 34–41. Male Clasping organ (CLA). 34. R. borealis, 35. R. cinerascens*, 36. R. herbicolens, 37. R. pelloniaria, 38. R. stigmatica, 39. R. tristrigalis, 40. T. prasonaria trilineata. 41–47. Male aedeagus. 41. R. borealis, 42. R. cinerascens*, 43. R. herbicolens, 44. R. pelloniaria, 45. R. stigmatica, 46. R. tristrigalis, 47. T. prasonaria trilineata. *Specimens and genitalia slide at ZSM-SNSB, Munich; slides and photos prepared by Dr Axel Hausmann.

FIGURES 48–62. Male genitalia images of Rhodostrophia and Tanaotrichia spp. 48–54. Male 8th Abdominal Sternite. 48. R. borealis, 49. R. cinerascens*, 50. R. herbicolens, 51. R. pelloniaria, 52. R. stigmatica, 53. R. tristrigalis, 54. T. prasonaria trilineata. 55–62. Female genitalia images of Rhodostrophia and Tanaotrichia spp. 55. R. borealis, 56. R. cinerascens*, 57. R. herbicolens, 58. R. pelloniaria, 59. R. stigmatica, 60. R. tristrigalis, 61. R. vinacearia, 62. T. prasonaria trilineata. *Specimens and genitalia slide at ZSM-SNSB, Munich; slides and photos prepared by Dr Axel Hausmann.