A new species of Spilogona Schnabl, 1911 (Diptera: Muscidae) from the Altai Mountains of Russia

Том 21. Вып. 2 Vol. 21. Iss. 2 CAUCASIAN ENTOMOLOGICAL BULLETIN Ростов-на-Дону 2025 РОССИЙСКАЯ АКАДЕМИЯ НАУК Южный научный центр RUSSIAN ACADEMY OF SCIENCES Southern Scientific Centre Кавказский энтомологический бюллетень 21(2): 281–286 Caucasian Entomological Bulletin 2025 A new species of Spilogona Schnabl, 1911 (Diptera: Muscidae) from the Altai Mountains of Russia © V.S. Sorokina Institute of Systematics and Ecology of Animals of the Siberian Branch of the Russian Academy of Sciences, Frunze Street, 11, Novosibirsk 630091 Russia. E-mail: s[email protected] Abstract. A new species of the genus Spilogona Schnabl, 1911 (Diptera), S. elegantissp.n., is described from the Altai Mountains. This species is distinguished by its notably broad male frons and parafacial, the presence of three postsutural dorsocentral setae, a stout spinose seta at the base of the mid femur in males, and spines on the postgenital plate in females. Both male and female specimens are described in detail, accompanied by comprehensive illustrations and photographs. Spilogona elegantissp.n. is morphologically similar to S. incerta Huckett, 1965. Comparative images of S.incerta are included, along with records of its distribution in Russia. Sequences of the cytochrome oxidaseI (CO1) gene for both species are provided and discussed. Key words: flies, distribution, CO1, Altai Republic, Russia, high altitudes, arctic latitudes. Новый вид из рода Spilogona Schnabl, 1911 (Diptera: Muscidae) с Горного Алтая (Россия) © В.С. Сорокина Институт систематики и экологии животных Сибирского отделения Российской академии наук, ул.Фрунзе, 11, Новосибирск 630091 Россия. E-mail: [email protected] Резюме. Описан новый вид Diptera с Горного Алтая– Spilogona elegantissp.n. Вид характеризуется очень широким лбом у самца и скулами, тремя постеродорсальными щетинками, шиповидной щетинкой в основании средних бедер у самцов, шипами на постгенитальной пластинке у самок. Описаны самцы и самки, приведены иллюстрации гениталий и фотографии габитуса. Новый вид близок к S.incerta Huckett, 1965. Приведены иллюстрации и местонахождения S.incerta в России. Предоставлены сиквенсы гена CO1 для нового вида и S.incerta. Ключевые слова: двукрылые, распространение, ген CO1, Республика Алтай, Россия, высокогорья, арктические широты. Introduction Most species of the genus Spilogona Schnabl, 1911 are adapted to cold environments and are particularly abundant at high altitudes and in arctic latitudes, where adults are commonly found near running water. Among mountain systems in Russia, the Altai Mountains have been the subject of the most comprehensive studies on the genus Spilogona, where the group is notably diverse and abundant [Sorokina, 2012, 2018]. To date, 53species have been recorded from this region. Research in the Russian Altai has significantly enhanced our understanding of the distribution of Spilogona species, not only within Russia but also across the entire Holarctic region. Numerous species originally described from North America have since been discovered in the Altai Mountains or in Arctic Russia [Sorokina, Khruleva, 2012; Sorokina, 2018; Sorokina, Shaikevich, 2018; Sorokina et al., 2018, 2023; Sorokina, Tridrikh, 2021, etc.]. Moreover, these studies have led to the discovery of several synonymies among species described concurrently in the Palaearctic and Nearctic regions [Sorokina, Michelsen, 2014; Sorokina, 2017, 2025]. Our investigations of high-altitude and arctic environments indicate that many Spilogona species exhibit an arcto-montane and circumpolar distribution, a pattern that greatly facilitates species identification in Russia. Despite the broad geographic range of many species, new species continue to be discovered across various regions of Russia, particularly in mountainous and northern areas. In this paper, we describe a new species of Spilogona from the Altai Mountains of Russia. Material and methods The Spilogona material used in this study is deposited in the Institute of Systematics and Ecology of Animals of the Siberian Branch of the Russian Academy of Sciences (SZMN, Novosibirsk, Russia), the Zoological Museum of the Moscow State University (ZMMU, Moscow, Russia), the Zoological Institute of the Russian Academy of Sciences (ZISP, St Petersburg, Russia), the National Museum of Natural History (Washington, DC, USA). Specimens were examined using an AltamiPSO745-T microscope (St Petersburg, Russia) for external morphological features. For dissection of the male and female terminalia, the tip of the abdomen was removed and boiled in 10%KOH solution for15–20s. After dissection and study, the abdomen and terminalia were washed and then stored in microvials of glycerine pinned directly underneath the specimens. The images were made with a Canon EOS 600D (Tokyo, Japan) camera mounted on a Zeiss Stemi 2000-C stereomicroscope (Oberkochen, Germany). Illustrations of male terminalia were made in ink and then edited using Adobe PhotoshopCS (San Jose, California, USA). DOI: https://doi.org/10.5281/zenodo.17820234 Research Article / Научная статья ZooBank Article LSID: urn:lsid:zoobank.org:pub:6C41FBC9-7589-4EB1-AF5E-DC3CF48A936A Body length was measured from the anterior margin of the head without antenna to the apex of the abdomen. Frons width was measured between the inner margins of the eyes. Morphological terms follow Cumming and Wood [2017]. The following abbreviations are used in the text: a– anterior seta, ad– anterodorsal seta, acr– acrostichal seta, av– anteroventral seta, d– dorsal seta, dc– dorsocentral seta, p – posterior seta, pd – posterodorsal seta, ph – posthumeral seta, ps– presutural seta, pv– posteroventral seta, v– ventral seta. Family Muscidae Subfamily Coenosiinae Tribe Limnophorini Spilogona incerta Huckett, 1965 (Figs 1, 3, 8–10) Spilogona incerta Huckett, 1965: 223 (type locality: “Fairbanks, Alaska” (USA; collectors Lienk and Jefferson)). Spilogona incerta: Sorokina et al., 2018: 327 (Magadan Region, Russia); Tridrikh, Sorokina, 2020: 88 (Magadan Region, Russia); Tridrikh, Sorokina, 2021: 827 (Magadan Region, Russia); Sorokina, 2025: 3 (Magadan Region, Russia). Notes. Spilogona incerta was first recorded from the Palaearctic region based on specimens collected in the Altai Mountains [Sorokina, 2018]. This species was originally described from Alaska, Fairbanks [Huckett, 1965]. It is characterized by a very wide male frons, densely whitish dusted parafacial and gena with a blackish reflection (visible from a certain angle), a dusted prementum, three narrow brownish vittae on the scutum, three postsutural dorsocentral setae, and a stout spinose seta at the base of the mid femur in males [Huckett, 1965]. The holotype of S. incerta has been examined. The Altai specimens differed slightly from the holotype, notably by possessing a wider parafacial and having very indistinct longitudinal stripes on the scutum. As S.incerta was previously known only from the holotype, and the terminalia had not been examined, the Altai specimens were provisionally identified as S. incerta, despite these minor differences. The species was subsequently included in the identification key for Spilogona of the Altai Mountains [Sorokina, 2018]. Recent studies of Muscidae from the Magadan Region of Russia [Sorokina et al., 2018; Tridrikh, Sorokina, 2020, 2021] yielded a series of specimens matching the holotype of S. incerta. The male terminalia were dissected and examined, revealing clear differences from the Altai specimens. Furthermore, DNA barcoding was conducted on specimens from both the Altai and Magadan populations. The results revealed distinct CO1 sequences, with an interspecific p-distance ranging from1.23 to1.38%. Despite the relatively low genetic divergence, the specimens from the two regions were assigned to different BINs in the BOLD system. These morphological and genetic differences confirm that the Altai population represents a species new to science. Distribution. Palaearctic: Russia, Far East (Magadan Region). Nearctic: USA (Alaska), Canada (Manitoba). DNA barcode. BOLD BIN: BOLD:ADZ7563. GenBank accession numbers: PQ388302, PQ388271 [Sorokina, 2025]. Spilogona elegantis sp. n. (Figs 2, 4–7) Spilogona incerta: Sorokina, 2018: 205, 208 (key), 240 (AltaiMts, misidentification). Material. Holotype, ♂ (SZMN): Russia, Altai Republic, Kosh-Agach District, upper part of Naryn-Gol River, 49°49ʹN / 89°32ʹE, 2520 m, 16–19.07.2009 (V.S. Sorokina). Paratypes: 2♂ (SZMN), Altai Republic, Ulagan District, Kurayskiy Range, 50°20ʹN / 87°45ʹE, 2500–2800 m, 29–30.06.2008 (A.V.Barkalov); 4♂, 2♀ (ZISP), Altai Republic, Ust’-Koksa District, Taimen’e Lake (Talmen Lake), lower part of Kharyuzovka River (tributary of Talmen Lake), 49°48ʹN/ 85°47ʹE, 1544m, water edge, moss on stones, larvae collecting / larvae breeding: 5.08.2012/15.08.2012 (A.A. Przhiboro); 1♂ (ZMMU), Altai Republic, Shebalino District, environs of Ust-Sema vill., 51°36ʹN / 85°48ʹE, 350 m, 21–26.06.2016 (N.E.Vikhrev). Diagnosis. The new species is similar to S.incerta because of the very wide male frons, 3postsutural dc setae and mid femur of male with a stout spinose seta at base, but it differs substantially from S.incerta by the wider parafacial and gena, very indistinct longitudinal stripes on scutum or their absence, rounded caudal margin of sternite5, and male terminalia. The new species can be distinguished as follows: wide frons, 3postsutural dcsetae, prementum dusted, postpedicel long, approximately 3.5–4 times as long as wide, notopleuron bare apart from the setae, anepisternum without interspatial setae, midfemur of male with a stout spinose seta at base, hind femur without pvsetae, postgenital plate of female with spines. Description. Male: body 5.5–5.7mm, wing 4–4.3mm. Head. Ground-colour black. Frons very wide, at level of anterior ocellus about as wide as distance between first pair ofdcsetae or wider, black with thick silvery dust, fronto-orbital plate, parafacial and gena silvery dusted with blackish reflections (visible from a certain angle). In lateral view, facial edge not projecting beyond level of profrons (Fig.2). Eye small, bare. Frons with 3pairs of frontal setae with hair-like setae between them, with 1–2pairs of orbital setae, ocellar, inner vertical and outer vertical setae long and strong. Parafacial at level of base of antenna 2times width of postpedicel, very weakly narrowing below. Height of gena about1/2 of height of eye and 4times width of postpedicel. Antenna black, postpedicel approximately 3.5–4 times as long as wide. Arista black, short pubescent, with longest individual hairsshorter than basal diameter of arista. Palpus black. Proboscis short, thin, prementum with dust. Labella large. Thorax. Ground-colour black. Scutum and pleura thickly whitish-grey dusted, without marks or with traces of longitudinal stripes along dc setae. Ground-hairs short. Presutural acr setae indistinct, 2 + 3dcsetae. Notopleuron bare apart from the setae. Anepisternum without interspatial setae. Katepisternal setae1 + 2. Scutellum thickly whitish-grey dusted, with small brownish lateral spots at base, without downwardly-directed preapical setulae on upper border of declivities. Wing. Light brownish tinged. Costa without spinules and costal spine. Calypters yellow. Haltere yellow. Legs. Ground-colour black, whitish-grey dusted. Fore tibia without psetae. Mid femur without any long setae except one stout spinose seta at base of ventral surface and one strong pand one pvseta at apex. Mid tibia withoutv, with 1ad and 2pd setae.Hind femur without pv setae, with 2 strong av setae on apical half. Hindtibia with 2–3av, 2ad, with 1pd and without pvsetae. Abdomen. Black, conical, yellowish-grey dusted, with triangular brown marks on tergites2–5. Sternite1 bare. Sternite5 large, with a wide and deep median notch, with rounded caudal margin and narrowly shining apex (Fig.7). 282 V.S. Sorokina Figs 1–4. Species of the genus Spilogona, habitus. 1, 3 – S. incerta; 2, 4 – S. elegantis sp. n. 1–2 – males; 3–4 – females. Scale bars 1 mm. Рис. 1–4. Виды рода Spilogona, общий вид. 1, 3 – S. incerta; 2, 4 – S. elegantis sp. n. 1–2 – самцы; 3–4 – самки. Масштабные линейки 1 мм. A new species of Spilogona 283 Terminalia. Cerci very wide in lateral view, sharply tapered towards the apex; surstylus wide at base and tapered towards blunt apex, not longer than cerci; epandrium large, hemispherical; hypandrium 1.5times shorter then epandrium (Fig.5); cercal plate rounded (Fig.6). Female (Fig.4): body 5.5–6mm, wing 4.5–5mm. Similar to male but differing by the wider and brownish frons, parafacial and gena yellow pruinose; scutum with 3more pronounced brown longitudinal stripes and brownish dust betweendc and intraalar setae; mid femur without a stout spinose seta at base of ventral surface; abdomen subshining, without brown spots on tergite5; postgenital plate with spines. Distribution. Palaearctic: Russia, AltaiMts. Etymology. The species name is based on the Latin adjective meaning “elegant” because the body is slim, not as stocky as in many species. DNA barcode. BOLD BIN: BOLD:ADZ2390. Remarks. The new species is morphologically very similar to S. incerta. But based on DNA barcodes, these species are genetically different; the p-distance between them is1.23–1.38%. Despite the low distance, the BOLD BIN between these populations turned out to be different. The intraspecific distance of S.elegantissp.n. specimens ranges from 0 to0.32%. Discussion At present, the Spilogona fauna of the Altai Mountains comprises 53species, including S.elegantissp.n. [Sorokina, 2018], making it the most diverse fauna among studied mountainous regions. The Altai fauna includes both widespread and “endemic” species. Some species are considered “endemic” to the region; however, this status is provisional, as many of the species can also be found in Arctic Russia or in northern parts of the Nearctic region (e.g., northern Canada and Alaska), consistent with the generally arcto-montane (inthe broad sense) distribution typical of the genus. Although the Altai region borders China, which harbors a comparable number of Spilogona species (61 species [Yu, Xue, 2015]), the overlap between their faunas is minimal. Only 12species (23%of the Altai fauna) are shared, indicating limited faunal similarity despite geographic proximity. The Spilogona fauna of the Altai Mountains shows greater similarity to the arctic and subarctic faunas of Russia and North America than to other neighboring Figs 5–10. Species of the genus Spilogona, details of structure. 5–7 – S. elegantis sp. n.; 8–10 – S. incerta. 5, 8 – terminalia, lateral view; 6, 9 – cercal plate, posterior view; 7, 10 – sternite5. Рис. 5–10. Виды рода Spilogona, детали строения. 5–7 – S. elegantis sp. n.; 8–10 – S. incerta. 5, 8 – терминалии, вид сбоку; 6, 9 – церки, вид сзади; 7, 10 – стернит 5. 284 V.S. Sorokina mountainous regions, despite the higher overall species richness in the latter areas. Currently, 108 species of Spilogona have been recorded from northern Russia [Sorokina, 2017, 2025; Sorokina, Pont, 2010; Sorokina et al., 2018; Sorokina, Tridrikh, 2021, etc.], and 117 species have been documented from the northern regions of the Nearctic, including Canada and Alaska [Huckett, 1965; Danks, 1981; Renaud et al., 2012]. Of the 53 Spilogona species found in the Altai, 70% (37species) are shared with the fauna of northern Russia, and 55% (29species) are also present in North America. Recent studies of the northern territories of Russia have revealed the presence of several Spilogona species previously described from the Altai Mountains, including S.decolorata Sorokina, 2018, S. improvisa Sorokina, 2018, S. khrulevae Sorokina, 2012, and S. platyfrons Sorokina, 2018. These species, originally found at high altitudes in the Altai, can no longer be considered endemic to the region. Their discovery in the Russian Arctic reinforces thestrong ecological and biogeographic connection between highmountain tundra and arctic faunas. Currently, 16species from the Altai Spilogona fauna have not yet been recorded in the Russian Arctic. Of these, nine species are restricted to lower elevations, primarily within the forest zone, and thus are less likely to occur at arctic latitudes. The remaining seven species are known only from high-altitude habitats and include S.antoninae Sorokina, 2018, S.colorata Sorokina, 2018, S.insolita Sorokina, 2018, S.longissima Sorokina, 2018, S.novgorodovana Sorokina, 2018, S.tanushka Sorokina, 2018, S.tara Sorokina, 2018. These high-altitude species may eventually be found at arctic latitudes, as was the case with previously described species. The new species described in this paper, is morphologically and genetically similar to S. incerta, a species originally known only from the subarctic region of Alaska. Itwas subsequently recorded from the subarctic region of Russia (Magadan Region) and was erroneously reported from the Altai Mountains [Sorokina, 2018]. Due to morphological similarities and the shared arctomontane distribution, the Altai specimens were initially identified as S. incerta. However, detailed morphological examination revealed several distinguishing characters that set the Altai specimens apart. Despite the relatively low genetic divergence, S. elegantissp. n. is here described as a distinct species based on a combination of morphological and molecular evidence. Acomparable case involves S. novgorodovana, recently described from high-altitude sites in the Altai, and S.sanctipauli (Malloch, 1921), a widespread circumpolar species. Although both species share a low level of genetic divergence (BOLD BIN: BOLD:AAM9109), they exhibit clear morphological differences. These cases may represent instances of recent divergence within species groups which may well occur in species with arcto-montane distribution. The study of the Muscidae fauna of the Altai Mountains remains incomplete, and further discoveries are anticipated, including both species new to science and additional “arctic” species. Notably, continued exploration at high altitudes is expected to yield the greatest increase in species diversity, as these environments have already proven to harbor both previously unknown and arcticdistributed species. These findings must be taken into account when identifying Spilogona species both at high altitudes and at arctic latitudes. Acknowledgements I would like to thank Andrei Przhiboro (StPetersburg, Russia) for collecting Muscidae in the Altai and for giving me this material to study. I am grateful to Jade Savage and Bishop’s University (Quebec, Canada) for the DNA barcoding data and for her help in interpreting these data. Ialso thank anonymous reviewers for important comments to my manuscript. The work was financially supported by the Federal Fundamental Scientific Research Program for 2021–2025 (project number 1021051703269-9-1.6.12). References Cumming J.M., Wood D.M. 2017. Adult Morphology and Terminology. In: Manual of Afrotropical Diptera. Volume1. Suricata4. Pretoria: South American National Biodiversity Institute: 89–133. Danks H.V. 1981. Arctic arthropods, a review of systematics and ecology with particular reference to the North American fauna. Ottawa: Entomological Society of Canada. 605p. Huckett H.C. 1965. The Muscidae of Northern Canada, Alaska and Greenland (Diptera). Memoirs of the Entomological Society of Canada. 97(Suppl.42): 1–370. DOI: 10.4039/entm9742fv Renaud A.K., Savage J., RoughleyR.E. 2012. Muscidae (Diptera) diversity in Churchill, Canada, between two time periods: evidence for limited changes since the Canadian Northern Insect Survey. The Canadian Entomologist. 144(1): 29–51. DOI: 10.4039/tce.2012.6 Sorokina V.S. 2012. Fauna of Muscidae (Diptera) of the Altai Mountains. In: Trudy Russkogo entomologicheskogo obshchestva. Tom 83(1). Entomologicheskie issledovaniya v Zapadnoy Sibiri [Proceedings of the Russian Entomological Society. Volume83(1). Entomological studies in Western Siberia]. StPetersburg: Zoological Institute of the Russian Academy of Sciences: 193–222 (inRussian). Sorokina V.S. 2017. The Muscoidea flies (Diptera) of the northern territories of Russia. Euroasian Entomological Journal. 16(1): 44–56 (inRussian). DOI: 10.15298/euroasentj.16.1.08 Sorokina V.S. 2018. Eleven new species of Spilogona Schnabl, 1911 (Diptera, Muscidae) from the Altai Mountains of Russia, with key to species. Zootaxa. 4410(2): 201–250. DOI: 10.11646/zootaxa.4410.2.1 Sorokina V.S. 2025. New taxonomic notes on the genus Spilogona Schnabl, 1911 (Diptera: Muscidae) in Arctic Russia, with the description of three new species. Zootaxa. 5584(1): 1–25. DOI: 10.11646/ zootaxa.5584.1.1 Sorokina V.S., Khruleva O.A. 2012. Details of species composition and distribution of house-flies (Diptera, Muscidae) of the Wrangel Island, Russia. Euroasian Entomological Journal. 11(6): 553–564 (inRussian). Sorokina V.S., Michelsen V. 2014. Contributions to the taxonomy and faunistics of some arctic species of Spilogona Schnabl (Diptera: Muscidae). Zootaxa. 3814(4): 512–520. DOI: 10.11646/ zootaxa.3814.4.4 Sorokina V.S., Pont A.C. 2010. An annotated catalogue of the Muscidae (Diptera) of Siberia. Zootaxa. 2597: 1–87. DOI: 10.11646/zootaxa.2597.1.1 Sorokina V.S., Shaikevich E.V. 2018. The identification of the species of the ‘Spilogona contractifrons species group’ and the ‘Spilogona nitidicauda species-group’ (Diptera, Muscidae) based on morphological and molecular analysis. European Journal of Taxonomy. 484: 1–26. DOI: 10.5852/ejt.2018.484 Sorokina V.S., Tridrikh N.N. 2021. An annotated checklist of the Muscidae (Diptera) of Chukotka (Russia), with new records. Annales de la Société entomologique de France (N.S.). 57(3): 205–234. DOI: 10.1080/00379271.2021.1939161 Sorokina V.S., Tridrikh N.N., ShaikevichE.V. 2023. Clarifying the taxonomic status and exploring hidden diversity in Graphomya minor RobineauDesvoidy, 1830 (Diptera: Muscidae: Mydaeinae) using molecular and morphological evidence. Annales de la Société entomologique de France (N.S.). 59(4): 233–248. DOI: 10.1080/00379271.2023.2222026 A new species of Spilogona 285 Sorokina V.S., Vikhrev N.E., TridrikhN.N. 2018. Apreliminary list of the Muscidae (Diptera) of the Magadan region, Russia. Annales de la Société entomologique de France (N.S.). 54(4): 318–334. DOI: 10.1080/00379271.2018.1484260 Tridrikh N.N., Sorokina V.S. 2020. A distribution analysis of Muscidae (Diptera) of the Northern Okhotia in Magadanskaya Oblast, Russia. Euroasian Entomological Journal. 19(2): 85–94 (in Russian). DOI: 10.15298/euroasentj.19.2.06 Tridrikh N.N., Sorokina V.S. 2021. Muscid fly (Diptera, Muscidae) distribution in river floodplain, forest and swamp biotopes of Northern Okhotia (Magadan Province, Russia). Entomological Review. 101(6): 820–836. DOI: 10.1134/S0013873821060075 Yu T., Xue W.Q. 2015. A key to Spilogona Schnabl (Diptera: Muscidae) from China, with descriptions of 13 new species. Annales de la Société entomologique de France (N.S.). 51(2): 161–195. DOI: 10.1080/00379271.2015.1063252 286 V.S. Sorokina Received / Поступила: 23.04.2025 Accepted / Принята: 26.05.2025 Published online / Опубликована онлайн: 5.12.2025