6. Hemistola zimmermanni (Hedemann, 1879)

(adults Figs. 14A, 14B, 16D, 17A, 57B–57D; male gen. Figs. 8–10, 34D–34F; female gen. Figs. 11, 12, 37F, 37G)

Hemistola zimmermanni: Viidalepp, 1976: 846; 1996: 61; Gordeeva & Gordeev, 2007: 129; 2020: 66; Mironov et al., 2008: 205; Beljaev & Mironov, 2019: 254. (Locus typicus: “Chingan” [Russia, Far East, Khingan Mountains]. Lectotype ♁, herewith designated to stabilize nomenclature (ZIN)).

Hemistola intermedia Djakonov, 1926: Beljaev & Mironov, 2019: 254. (Locus typicus: Minusinsk [Russia, Krasnoyarsky Kray]. Lectotype ♁, herewith designated to stabilize nomenclature (ZIN)).

? Hemistola chrysoprasaria intermedia: Viidalepp, 1996: 61 .

Type material examined. Lectotype ♁ of Geometra zimmermanni Hedemann, 1879 (hereby designated) (Fig. 14A): [Russia:] <small brownish quadrat with handwritten text> ‘Chingan | Geb. | 28/7. [18]77’, <small whitish quadrat with handwritten text> ’61.’, <yellowish rectangular label with printed text> ‘Колл. Вел. КнЯЗЯ | НиколаЯ | Михайловича.[collection of Grand Duke Nikolai Mikhailovich]’, <large rectangular label with red handwritten text> ‘ Geometra | Zimmermanni Hedem. | Type.’, <red rectangle with handwritten text> ‘<underlined> LECTOTYPUS ♁ | Geometra | zimmermanni | Hedemann, 1879 | Design. I. A. Makhov 2023’.

Lectotype ♁ of Hemistola intermedia Djakonov, 1926 (hereby designated) (Fig. 14B): [Russia, Krasnoyarsky Kray:] <small rectangular label with printed text> ‘Минусинск [Minusinsk] | <handwritten> 6.VII.[19]24 | <printed text> Филипьев [Filipjev]’ [on the back of the label:] <handwritten text> ‘ГрЯДы’ [Gryady]; <handwritten text> ‘ Hemistola intermedia Djak. | <printed text>A. Djakonov det.’, <red rectangle with handwritten text> ‘<underlined> LECTOTYPUS ♁ | Hemistola | intermedia | Djakonov, 1926 | Design. I. A. Makhov | 2023’.

Further material. Krasnoyarsky Kray: 1 ♁: “Окр. Минусинска 9.VII.1928 Кожанчиков [Vicinity of Minusinsk, 9.VII.1928, Kozhantchikov]” [on the back of the label:] “Тагарск. остр. [Tagarsky Island]”; 1 ♁: “МинусинскЕнис. г. 21.VII.1925. Кравченко и Цыганков [Minusinsk, Yeniseskaya Governorate, 21.VII.1925, Kravchenko & Tsygankov]” [on the back of the label:] “Тагар. остр. [Tagarsky Island]”; 1 ♁: “МинусинскЕнис. г. 16.VII.1925. Кравченко и Цыганков” [on the back of the label:] “Тагар. остр. [Tagarsky Island]” | “ Hemistola zimmermanni Hed. det. W. Koshantschikov”; 1 ♁: “МинусинскЕнис. г. 16.VII.1925. Кравченко и Цыганков” [on the back of the label:] “Тагар. остр.”; 1 ♁: “Окр. Минусинска 23.VII.1936 Кожанчиков” [on the back of the label:] “ГрЯДы”; 1 ♁: “Окр. Минусинска 19.VII.1928 Кожанчиков” [on the back of the label:] “Таг. остр. [Tagarsky Island]”; 1 ♁: “Окр. Минусинска 12.VII.1937 Кожанчиков” [on the back of the label:] “ГрЯДы”; 1 ♁: “Окр. Минусинска 15.VII.1937 Кожанчиков” [on the back of the label:] “ГрЯДы”; 1 ♁: “Окр. Минусинска 31.VII.1937 Кожанчиков” [on the back of the label:] “ГрЯДы”; 1 ♁: “Окр. Минусинска 23.VII.1936 Кожанчиков” [on the back of the label:] “ГрЯДы”; 1 ♁: “Окр. Минусинска 12.VII.1937 Кожанчиков” [on the back of the label:] “ГрЯДы”; 1 ♁: “МинусинскЕнис. г. 14.VII.1925. Кравченко и Цыганков” [on the back of the label:] “Тагар. остр.”; Minusinsky Distr., close to Bystraya vill., Grjady, steppe hills (S-exposition slope: 53°44’21”N, 91°33’38”E, 358 m. a.s.l.), at light, 19. VI.2020, 1 ♁ (GenBank ID: OQ 362117), R. Maksimov [ZIN]. Republic of Khakassia: Ust’-Abakansky Distr., Khakassky state National Reserve, Oglahty area, motley grass steppe, rocky hills (53°59’17”N, 91°29’46”E, 309 m. a.s.l.), at light, 3.VII.2018, 2 ♁ (GenBank ID: OQ 362115, OQ362116), R. Maksimov [ZIN]. Irkutskaya Oblast: Sarma, 22.VII.2019, 1 ♁, 1 ♀; Tazheranskaya steppe, 23.VII.2019, 9 ♁, 5 ♀; same loc., 28.VII.2020, 4 ♀ (GenBank ID: OK 073174), I. Makhov [ZIN]. Buryatia: Ulan-Ude, 24.VII.1956, 1 ♁; same loc., 11.VII.1956, 1 ♁, unknown collector; Kurba, 16–22.VII.1973, 2 ♁; Petropavlovka, 27.VII.1974, 1 ♁, A. Tarmaeva [ISEA]; Dobo-Yenkhor, 15.VII.2008, 1 ♁, T. Gordeeva [IGEB]; Tatarsky Klyuch, 2.VII.2020, 1 ♁; Gusinoye, 1.VII.2016, 1 ♁ (GenBank ID: MZ 148333), 2 ♀ (GenBank ID: MZ 148334, MZ 148335), 3 ♀, 8 spms.; Beloozersk, 3.VII.2016, 2 spms.; Bayan, 5–6.VII.2016, 2 spms.; M. Tasarkhay, 7–8.VII.2016, 2 ♁, 2 ♀, 6 spms.; Tarbagatay, 13.VII.2018, 13 ♁ (GenBank ID: MZ 148328, MZ 148329); same loc., 23.VII.2021, 40 ♁, 2 ♀, I. Makhov [ZIN]. Zabaikalsky Kray: Borzinsky Distr., Daursky Nature Reserve, Adon-Chelon, 1.VIII.2022, 1 ♀, A. Stekolshchikov; Sretensky Distr., Shilka river valley, 4.5 km NE of Molodovsk vill. (52°16’58”N 117°55’30”E), 11.VII.2020, 2 ♁, 1 ♀; Kuenga river valley, 3 km N of Dunayevo vill. (52°05’53”N 117°02’24”E), 8.VII.2020, 10 ♁ (GenBank ID: MZ 148330, MZ 148331, MZ 148332); same loc., 9.VII.2020, 3 ♁, 1 ♀; same loc., 10.VII.2020, 3 ♁, Nerchinsky Distr., Nercha river valley, vicinity of Nerchinsk vill. (51°59’01”N 116°31’15”E), 8.VII.2020, 2 ♁, I. Makhov [ZIN].

Distribution. Siberian–Far Eastern, subboreal. From southern part of Krasnoyarsky Kray and Khakassia to Primorye. Outside Russia in Mongolia, N and NE China, N and central Korea.

Hostplants: unknown.

Remarks. The species H. intermedia was described from the environs of Minusinsk (the south of Krasnoyarsky Kray) by Djakonov (1926). He noted that H. intermedia on the average smaller than H. zimmermanni and H. chrysoprasaria, however, the main differences of this taxon from the closer H. zimmermanni were the shortened antennal pectinations and relatively longer coecum of aedeagus: “the strongly elongated coecum in the new species is considerably longer and thinner [than in H. zimmermanni]: it is 3.5 times shorter than the length of the phallos, while in H. zimmermanni (and in vernaria [= H. chrysoprasaria]) coecum is 4.5 times shorter than the length of the phallos.”

The status of the taxon H. intermedia remained unclear. Wehrli (1929) supposed that H. intermedia might be either a mere form of H. zimmermanni or a young species incompletely differentiated from H. chrysoprasaria . Viidalepp (1996) interpreted intermedia as a subspecies of H. chrysoprasaria . In the first edition of the Catalogue of the Lepidoptera of Russia (Mironov et al. 2008) H. intermedia was not mentioned, however, later, E.A. Beljaev and V.G. Mironov considered H. intermedia a good species (Beljaev 2016; Beljaev & Mironov 2019). The moths of this group from nearby regions (Republic of Tuva, Altaisky Kray, Irkutskaya Oblast) have traditionally been identified as H. zimmermanni (Viidalepp 1976, 1996; Volynkin et al. 2011).

When comparing “ H. intermedia ” from the type locality and nearby regions with the Far Eastern H. zimmermanni, indeed, the difference in the size of the individuals and in the length of the antennal pectinations is obvious. The moths from the eastern part of the range are generally much larger than those from the west; however, the serial material from different regions (Krasnoyarsky Kray, Irkutskaya Oblast, Buryatia, Zabaikalsky Kray, Amurskaya Oblast, Khabarovsky Kray, Primorsky Kray, Mongolia) shows that individuals vary markedly in size. In one location, along with moths of the usual size, very small individuals are sometimes found. In my opinion, the main diagnostic feature of H. intermedia indicated by Djakonov (shortened pectinations of antennae) fits into variability spectrum of H. zimmermanni . The moths of H. zimmermanni considerably vary in size throughout their range, and as a result, different parts and appendages (including the processes of flagellomeres) vary proportionally. For clarity, we can compare the antennae in Fig. 7. It shows the antennae of males from the western part of the range to the eastern one (A, C, E, G, I, K). On the right, the 10 th flagellomeres of the corresponding antennae are presented separately. When comparing the antenna of the male from the type locality of H. intermedia (Figs. 7A, 7B) and the antenna of the male from Khabarovsky Kray (Figs. 7I, 7J), it can be seen that flagellomere processes are indeed different. However, the difference in the total length of the antenna must also be taken into account. At the bottom of the figure these two antennae are aligned in length. It is obvious here that the difference in length of the processes of flagellomeres is hardly noticeable, although these antennae belong to tentatively different species.

The second features used by Djakonov as diagnostic for H. intermedia is the length of coecum of aedeagus. I have studied at least 15 samples from different locations and found no difference in the coecum length between “ H. intermedia ” and H. zimmermanni . Several phalloses from the males collected in different regions (from west to east) are presented in Fig. 8. Thus, the diagnostic characters the lengths of the coecum, as well as the length of antennal pectinations seem to be unreasonable. Regarding to the male genital segment and sternite A8, there are also no evident differences between “ H. intermedia ” (Figs. 9A–9G) and H. zimmermanni (Figs. 10A–10H).

It is noteworthy that the shape and size of lamella postvaginalis in female genitalia are also somewhat variable (Figs. 11, 12). Occasionally, the appearance of the lamella postvaginalis is clearly different in moths collected from the same location on the same date (compare Figs. 11A and 11B; Figs. 11C and 11D; Figs. 11E, 11F, 11G and 11H; Figs. 12A and 12B). Nevertheless, when studying the serial material, these differences form a series with a gradual transition of shape of lamella postvaginalis, therefore, in my opinion, they are not diagnostic. At the same time, the female genitalia of H. chrysoprasaria reliably differ from those presented in Figs. 11, 12 by the absence of semicircular furrow on the lamella postvaginalis (Fig. 37E).

It was previously shown that the moths corresponding to the features of H. zimmermanni from Irkutskaya Oblast, Buryatia and Zabaikalsky Kray were genetically homogeneous (Makhov & Lukhtanov 2021). Later, I have obtained three COI sequences of the moths collected in the type locality of H. intermedia (Krasnoyarsky Kray, see “Material examined”). Analysis of these sequences shows that they are almost identical to the sequences we analysed earlier (moths from Irkutskaya Oblast, Buryatia and Zabaikalsky Kray). New genetic data from moths in Minusinsky District of Krasnoyarsky Kray and from Ust’-Abakansky District of Khakassia was included in the COI dataset (the data obtained by us and the data available in the GenBank and BoLD) and used to build a Bayesian tree (Fig. 13). The mentioned specimens Hml1, Hml2 and Hml3 (highlighted in red) fall into the same clade with the samples from the Siberian regions and from China identified as H. zimmermanni . The samples Hml1 and Hml2 (Republic of Khakassia) are placed in the same subclade together with samples from Buryatia, Zabaikalsky Kray and Irkutskaya Oblast. Thus, DNA barcoding of “ H. intermedia ” from the type locality and adjacent areas does not confirm the assumption of the independence of this taxon.

Taking into account the morphological aspects considered above and the lack of COI differentiation between “ H. intermedia ” and H. zimmermanni, H. intermedia is considered here a synonym of H. zimmermanni syn. n., only being a small form of H. zimmermanni in the western part of its area.