Ypthima thao Monastyrskii & Lang, 2022

Monastyrskii, Alexander L., Lang, Song-Yun, Uémura, Yoshinobu & Lien, Vu Van, 2022, A new species related to Ypthima praenubila Leech, 1891 in Vietnam and China (Lepidoptera, Nymphalidae, Satyrinae), Zootaxa 5141 (1), pp. 71-78 : 73-77

publication ID	https://doi.org/ 10.11646/zootaxa.5141.1.6
publication LSID	lsid:zoobank.org:pub:D02A3A98-B0F2-4429-A3A8-77F299F69907
DOI	https://doi.org/10.5281/zenodo.6580452
persistent identifier	https://treatment.plazi.org/id/67359566-FFC9-FF8E-FF09-0B74BE15AA7D
treatment provided by	Plazi
scientific name	Ypthima thao Monastyrskii & Lang
status	sp. nov.

Treatment

Ypthima thao Monastyrskii & Lang View in CoL sp. nov.

( Figure 2 View FIGURE 2 )

Description. Male. Forewing length: HT 25.5 mm; PTs 27, 26, 26, 24.5, 26, 25.5, 26.5, 25, 26, 27, 25, 26.5, 24, 25, 26, 26, 25, 25, 25, 25.5, 24.5 (n = 22; mean = 25.52 mm).

Forewing upperside ( Figure 2A View FIGURE 2 ): Ground colour uniformly dark brown; inner and outer discal fasciae absent; submarginal fascia indistinct; marginal fascia weakly developed; subapical eyespot between veins M 3 and M 1 black, well developed, oval, bipupilled with indistinct yellowish ring that is sometimes nearly invisible; subapical eyespot surrounded by brownish area, slightly paler than ground colour; the area of the scent brand invisible to the naked eye; fringe brown.

Androconia ( Figure 3A View FIGURE 3 ): Length: 0.18–0.19 mm; triangular with a broad base and longer apical portion; terminal brush thick.

Forewing underside ( Figure 2B View FIGURE 2 ): Ground colour greyish brown; inner discal fascia absent, but outer discal and submarginal fasciae well developed; area from base to outer discal fascia densely striated with dark brown; area between outer discal and submarginal fasciae sparsely and delicately striated; subapical eyespot larger and more round than that on the upperside, and broadly yellow-ringed; fringe brown.

Hindwing upperside ( Figure 2A View FIGURE 2 ): Ground colour uniformly dark brown; inner and outer discal fascia absent; submarginal fascia absent; unipupilled eyespot located in cell Cu 1a; minute eyespot in cell Cu 1b absent; fringe greyish.

Hindwing underside ( Figure 2B View FIGURE 2 ): Ground colour uniformly light grey; inner and outer discal fasciae absent; submarginal fascia indistinct; wing surface irregularly striated with dark brown, from base to discal area streakiness dense; broad greyish postdiscal area sparsely striated; two equal unipupilled eyespot located in subapical cell R s and subtornal cell Cu 1a; smaller bipupilled eyespot in cell Cu 1b present.

Female: Forewing length: PT: 27.5 mm.

Forewing upperside ( Figure 2C View FIGURE 2 ): Ground colour uniformly brown; inner and outer discal fasciae absent; submarginal fascia indistinct; subapical black bipupilled eyespot larger than that in the male, yellowish ring well developed and rather thick; the eyespot surrounded with paler brown area that is characteristic of many female Ypthima spp. ; fringe brownish.

Forewing underside ( Figure 2D View FIGURE 2 ): Ground colour greyish-brown; inner discal fascia absent; outer discal and submarginal fasciae well developed; area from base to outer discal fascia densely striated with brown; streakiness between outer discal fascia and submarginal fascia paler brownish and streaks smaller and delicate; subapical black bipupilled eyespot surrounded with yellow ring similar to that on the upperside; fringe brownish.

Hindwing upperside ( Figure 2A View FIGURE 2 ): Ground colour uniformly dark brown; inner and outer discal fascia absent; submarginal fascia absent; unipupilled eyespot located in cell Cu 1a; single minute eyespot absents in cell Cu 1b; fringe greyish.

Hindwing underside ( Figure 2B View FIGURE 2 ): Ground colour uniformly light grey; inner and outer discal fasciae absent; submarginal fascia indistinct; wing surface irregularly striated with dark brown: from base to discal area streakiness dense; broad greyish postdiscal area sparsely striated; two equal unipupilled eyespot located in subapical cell R s and subtornal cell Cu 1a; smaller bipupilled eyespot present in cell Cu 1b.

Male genitalia ( Figure 4A–C View FIGURE 4 ): Tegumen in dorsal view narrowed posteriorly; fenestrula of a small membranous area at dorsum; uncus longer than length of tegumen and approximately straight and slightly curved ventrally in distal part ( Figure 4 C View FIGURE 4 ). Subanal area of diaphragma strongly sclerotized and invaginated as a long sclerotic pouch (SaP) ( Figure 4B View FIGURE 4 ), which is distinctly longer than tegumen+uncus; ventral side of this pouch bears paired structures supporting the direction of phallus besides the juxta. Saccus about a third as long as vinculum; phallus nearly straight with smooth bending at dorsum. Valvae relatively narrow and long; broad from base to middle zone; from middle zone, costa and sacculus smoothly curved; apical third with sharply narrowing dorsal and ventral sides, and forming a long toothed apex ( Figure 4A, B View FIGURE 4 ).

Female genitalia ( Figure 5A–C, G, H View FIGURE 5 ): Bursa copulatrix ( Figure 5G View FIGURE 5 ) with a globular, oval shape. A pair of equally elongated signa ( Figure 5 C, G View FIGURE 5 ) spindle-shaped, slightly curved and fused with each other on the anterior portion; length of touch more than half of signa length; surfaces of signa uniformly and densely dotted with minute spines ( Figure 5C View FIGURE 5 ). Antrum well developed ( Figure 5A, B View FIGURE 5 ). Ostium bursae surrounded by the well sclerotized sterigma ( Figure 5A, B, H View FIGURE 5 ) which has a specific shape. Lamella antevaginalis (La) well developed and strongly sclerotized; this thin plate narrow at base and broadened distally ( Figure 5A View FIGURE 5 ). Lamella postvaginalis (Lp) with a cylindrical structure, at its apex (distally) it separated into two blades (Bl).

Diagnosis. The new species closely resembles Ypthima praenubila , which is distributed in southern China (including Taiwan and Hainan islands), and northern to central Vietnam ( Uémura & Monastyrskii, 2004; Monastyrskii and Devyatkin, 2003, 2015; Hsu, 2013; Chou, 1994). Males and females of both species have structurally similar genitalic morphology. The genitalia of these two taxa initially appeared quite similar with differences typically associated with subspecifies-level differentiation. However, detailed observation evinces a number of differences between the two taxa that demonstrate their status as separate species: 1. Both sexes of the new species are smaller than Y. praenubila (means of the forewing length [ Y. thao vs Y. praenubila ] 25.7 vs 29.7 mm in males and 27.5 vs 33.1 mm in females). 2. The ground colour of both sexes of Y. thao is paler than that of Y. praenubila , and the androconial zone on the male forewing upperside is not visible to the naked eye. 3. Both sexes of Y. thao have three submarginal eyespots on the hindwing underside while Y. praenubila has four. 4. The new taxon usually lacks a minute eyespot in cell Cu 1b, whereas it is usually present in Y. praenubila . 5. The androconia of both taxa are similar in size but different in shape. In Y. thao , the androconia are triangular with a broad basal side and terminally thicker bristles, whereas in Y. praenubila the slender apical portion is shorter and bears a small bundle of short, featherlike hairs ( Figure 3 View FIGURE 3 ). 6. The valva and uncus of the male genitalia in Y. thao ( Figure 4 A, B View FIGURE 4 ) differ from those of Y. praenubila ( Figure 4 D, E View FIGURE 4 ); in comparison with these characters (see description above), valvae in Y. praenubila are narrow and long, basally broad, and gradually narrow to the apex, which is sometimes bent inwardly; the uncus is smoothly and symmetrically curved. 7. The female genitalia of Y. thao differs from Y. praenubila in the shape of the lamellae of the antevaginalis, postvaginalis, sterigma ( Figure 5A, B, H and D, E, J View FIGURE 5 ), and the signa ( Figure 5 C and F View FIGURE 5 ). In the new species, the apical part of the lamella postvaginalis is divided into two blades ( Figure 5A, B, H View FIGURE 5 ) whereas in Y. praenubila the apical part of this lamella is broadly widened ( Figure 5D, I, J View FIGURE 5 ); the lamella antevaginalis of the new species is triangular ( Figure 5A View FIGURE 5 ), but in Y. praenubila it is T-shaped.

Type material: Holotype: ♂, NORTHERN VIETNAM: Ha Giang province, Dong Van district V–VI.2016, leg. LC . Paratypes: 19♂, the same locality as HT: V – VI.2017 ; V – VI.2007 ; leg. LC; 1♂, NORTHERN VIETNAM: Vinh Phuc province, Phuc Yen town, Me Linh station for Biodiversity , 22. VI.2017 , leg. VVL; 1♀, Vinh Phuc province, Tam Dao N.P., VI.2004 , forest at 900 m, leg. VVL; 1 ♂, SOUTHWESTERN CHINA: Southeastern Yunnan, Malipo, Laoshan Reserve , 1580 m, 29.IV.2019, leg. S.Y. Lang.

Depositing: HT and some PTs will be deposited in VNMN; other paratypes will be delivered to CQNHM, LSY, TME and NHM .

Distribution: So far, the new species is recorded from northern Vietnam (Vinh Phuc and Ha Giang provinces) and southwestern China (southeastern Yunnan province) near the Vietnam / China border.

Phenology. Like Ypthima praenubila , Y. thao has been recorded from April to June.

Etymology. The species name “thao is dedicated to Mrs. Thao, who is the wife of the first author and has supported him butterfly study during much of his life in Vietnam and during the challenging COVID pandemic.