Isochlora arctomys Alphéraky, 1897

Volynkin, Anton V., Titov, Sergey V., Matov, Alexey Yu., Tóth, Balázs, Saldaitis, Aidas, Rakhimov, Ruslan D. & Egorov, Petr V., 2023, On the taxonomy of the genus Isochlora Staudinger with descriptions of two new species from Mongolia and Qinghai, China (Lepidoptera: Noctuidae: Noctuinae), Zootaxa 5374 (3), pp. 409-423 : 414-415

Isochlora arctomys Alphéraky, 1897

( Figs 9–12 , 24, 25 , 29 )

Isochlora arctomys Alphéraky, 1897 , in Romanoff, Mémoires sur les lépidoptères, 9: 43, pl. 2, figs. 11–12 (Type locality: [ China, Xinjiang, E of Urumchi, Bogda Shan Mts] “ Bogdo-Ola ( Thian-chan septentrional-oriental)”)

= Chamyla idia Staudinger, 1900 , Deutsche entomologische Zeitschrift Iris, 12(2): 343, pl. 7, fig. 9 (Type locality (hereby fixed by lectotype designation): [ China, Xinjiang, eastern Thien Shan Mts, Barkultag Ridge near Hami ] “östlichsten Ausläufern des gewaltigen Thian Schan-Gebirges ... Stadt Chamyl ”), syn. rev.

Type material examined. Lectotype of Isochlora arctomys (hereby designated) ( Figs 9 , 24 ): male, “Bogdo | Ala.” (upper side) | “ Gr. Gr. ” [Grum-Grshimailo] (under side) / “Idia Stgr. ” / “64.” / “ Coll. Gr. [and] Dk.[Duke] | Nikolay | Mikhailovich” (in Russian) / “Slide | AV7367³ | A. Volynkin ” ( ZISP); paralectotypes: 1 female, “Bogdo | Ala.” (upper side) | “ Gr. Gr. ” [Grum-Grshimailo] (under side) / “Idia Stgr. | Iris XII” / “64.” / “ Coll. Gr. [and] Dk.[Duke] | Nikolay | Mikhailovich” (in Russian) / “Slide | AV7369 ♀ | A. Volynkin ” ( ZISP); 1 female, green label “Bogdo | Ala.” (upper side) | “ Gr. Gr. ” [Grum-Grshimailo] (under side) / “ Coll. Gr. [and] Dk.[Duke] | Nikolay | Mikhailovich” (in Russian) / “Slide | AV7368 ♀ | A. Volynkin ” ( ZISP); 1 female, green label “Bogdo | Ala.” (upper side) | “ Gr. Gr. ” [Grum-Grshimailo] (under side) / “ Coll. Gr. [and] Dk.[Duke] | Nikolay | Mikhailovich” (in Russian) ( ZISP).

Lectotype of Chamyla idia (hereby designated) ( Figs 12 , 25 ): male, brown label “Thian or. | [18]96 Hbhr. [Haberhauer]” / pink label “Origin.” / “ Chamyla | Stgr. | Arctomys Alph. | Idia | Stgr.” / “Préparation | Bo M.B. 155 | Ch. Boursin ” ( MfN); paralectotypes: 1 female, brown round label / pink label “Origin.” ( MfN); 1 female, brown round label / pink label “Origin.” / “abgeb.[ildet]” [=illustrated] ( MfN).

Remarks. (1) Isochlora arctomys was described from one male and three females ( Alphéraky 1897). In order to stabilise the nomenclature, the male syntype deposited in ZISP is hereby designated as the lectotype. (2) Chamyla idia was described based on one male and two females from eastern Tien Shan and a female from Korla. In order to stabilise the nomenclature, the male syntype with the label “Thian or.” deposited in MfN is hereby designated as the lectotype, and its place of origin, following the Article 76.2 of ICZN (1999), becomes the type locality of the taxon. (3) Poole (1989) listed idia as a junior synonym of arctomys . However, in their check-lists of the genus Isochlora, Hreblay et al. (1998) and Gyulai & Ronkay (2006) placed idia in the synonymy with arctomys with a question mark. Both the taxa are described from the same easternmost region of the Tien Shan Mountain Massif, and their lectotypes display no remarkable morphological differences from each other therefore the synonymic status of idia is revised in the present paper.

Diagnosis. The forewing length is 14.0–15.0 mm in both sexes. The species ( Figs 9–12 ) is clearly different from most congeners due to its greyish-brown forewing colouration with a diffuse pattern, and is most superficially reminiscent of species of the I. glaciale ( Boursin, 1940) lineage (illustrated by Babics et al. (2008) and Volynkin & Titov (2020)), from which I. arctomys differs in the narrower forewing and the indistinct or dentate transverse lines on the forewing. In the male genitalia, I. arctomys can be easily distinguished from the I. glaciale lineage by the lack of the harpe and the cornuti in the phallus vesica. Despite the external dissimilarity, the male genitalia of I. arctomys ( Figs 24, 25 ) are very similar to I. intricans ( Fig. 23 ) and I. hreblayi sp. n. ( Fig. 22 ), from which the current species differs only in the shorter uncus and the narrower valva. Additionally, compared to I. intricans , I. arctomys lacks the harpe and the proximal cornuti in the phallus vesica. The female genitalia of I. arctomys ( Fig. 29 ) are distinguished from I. intricans ( Fig. 28 ) by the considerably longer and funnel-shaped antrum (it is shallow bowl-shaped in the congener), the shorter membranous section of the ductus bursae, and the corpus bursae lacking the signa.

Distribution. Northwestern Xinjiang Uygur Autonomous Region, China ( Fig. 33 ).

Figures

FIGURE 33. Distribution map of Isochlora spp. in the Tien Shan Massif and Mongolian Altai.

FIGURES 9–12. Isochlora arctomys: adults. Depositories of the specimens: 9–11 in ZISP; 12 in MfN.

FIGURES 24–27. Isochlora spp.: male genitalia. Depositories of the specimens dissected: 24, 26 and 27 in ZISP; 25 in MfN.

FIGURES 28–32. Isochlora spp.: female genitalia. Depositories of the specimens dissected: 28, 29, 31 and 32 in ZISP; 30 in MfN.

FIGURES 20–23. Isochlora spp.: male genitalia. Depositories of the specimens dissected: 20 and 21 in MfN; 22 in MH/ HNHM; 23 in ZISP.