Sepedon spinipes flavifrons, Vikhrev & Yanbulat, 2023

Vikhrev, Nikita E. & Yanbulat, Maria O., 2023, Further notes on Asian fauna of Sepedon (Diptera, Sciomyzidae), Amurian Zoological Journal XV (3), pp. 650-656 : 651-652

Sepedon spinipes flavifrons , subsp. nov. Figs 2, 3

https://zoobank.org/References/eee41a7f-963c-4153- abf6-751f331c2d01

Holotype, male, RUSSIA, Khabarovsk near airport, 48.53°N, 135.13°E, 5– 7.06.2022, N. Vikhrev & M. Yanbulat, stored in ZMUM.

Paratypes 14♂, 16♀: RUSSIA: Amur Reg., Zeya (53.77°N, 127.28°E): 20.06.1978, A. Shatalkin , 1♀; 12– 14.09.1981, A. Shatalkin, 3♂, 7♀ (all ZMUM) ; Khabarovsk Reg.: Bychikha env. (48.30°N, 134.82°E): 16.05.1973, K. Gorodkov , 1♂ ( ZIN) ; 25.07.2020, O. Kosterin, 2♂, 1♀; 9.08.2020, O. Kosterin, 1♂ ( ZMUM) ; Khabarovsk near airport, 48.53°N, 135.13°E, 5– 7.06.2022, N. Vikhrev & M. Yanbulat , 1♂ ( ZIN) ; Khabarovsk, suburb, 48.53°N, 135.13°E, 5– 7.06.2022, N. Vikhrev , 2♂, 2♀ ( ZMUM and ZIN) ; Komsomolsk-Amur , Mylki L., 50.50°N, 136.97°E, 21.06.2022, N. Vikhrev , 1♀ ( ZMUM) ; Mayak env., 48.9°N, 136.19°E, 6.06.2022, N. Vikhrev , 1♀; 24.06.2022, N. Vikhrev, 1♀ ( ZMUM) ; Prymorsky Reg.: Lake Khanka near Platono- Aleksandrovka village , 45.061°N, 131.99°E, 1.08.2020, O. Kosterin , 1♂ ( ZMUM) ; Spassk- Dalny (44.6°N, 132.82°E), 20.08.1993, S. Belokobylsky , 1♂ ( ZIN) ; Yakutia Reg. : 7 km N of Yakokit , 58.95°N, 125.85°E, an oxbow lake, 24– 27.06.2022, O. Kosterin , 1♀ ( ZMUM) ; Olyokminsk env., Kyachchi (60.35°N, 120.10°E), 20.07.2008, A. Ovchinnikov , 1♀ ( ZIN) ; Zabaykalsky Reg., Solontsy env., 51.45°N, 118.85°E, 14.06.2023, V. Zinchenko , 2♂ ( ISEA) .

Distribution. E Asia, where known from 119°E to 136°E and from 60°N to 45°N.

Diagnosis. We found no differences between S. spinipes flavifrons subsp. nov. and the nominotypical S. s. spinipes either in the genitalia structure or in the non-genitalic characters, except for the absence of the dark frontal spots. In S. spinipes flavifrons subsp. nov., parafacial spots under the antennae are present and distinct, but the area of the frontal spots is not black, it is only slightly darker yellow than the surface of the frons around it (compare Fig. 1 and Figs 2, 3).

Discussion. In the field season 2022, we found that all specimens of S. spinipes Scopoli, 1763 from Khabarovsk Region of the Russian Far East had no dark frontal spots. This contradicts the identification key and photo illustrations given in our work on the Asian Sepedon ( Vikhrev & Yanbulat 2019: 48–49 and figs 1, 4). This also contradicts the identification key and photo illustrations given in the work on the Chinese Sepedon ( Li & Yang 2017: 303 and figs 68–70). Vikhrev & Yanbulat (2019: 52) shortly mentioned that there are “...several specimens of S. spinipes in which the normally black frontal spots are represented by yellowish stains only”. This time we’ve reexamined our rich material of S. spinipes in ZMUM and ZIN and found a clear geographical trend in distribution of specimens with or without dark frontal spots, the trend permits to regard these specimens as two subspecies. Nominotypical S. spinipes spinipes , with black frontal spots, is distributed from W Europe to Central Yakutia , while S. spinipes flavifrons ssp. nov., without black frontal spots, is distributed from Central Yakutia to the Far East, the border between two subspecies runs at longitudes 119– 129°E.

The examined material from the easternmost localities for the nominotypical subspecies was as follows:

Buryatia reg.: Tunka env., 51.7°N, 102.6°E, 750 m, 7– 11.06.2021, N. Vikhrev, 3♂ ;

Kyren env., 51.7°N, 102.1°E, 750 m, 16– 19.06.2021, N. Vikhrev, 2♂, 1♀ ( ZMUM) ;

Irkutsk Reg., Slyudyanka , 51.68°N, 103.69°E, 480 m, 27– 29.06.2021, N. Vikhrev, 1♀ ( ZMUM) ;

Yakutia Reg. : Zhigansk (66.77°N, 123.37°E), 15.08.1973, K. Gorodkov, 1♂; Olyokminsk (60.37°N, 120.40°E), 31.08.1988, K. Gorodkov, 7♂, 3♀ ; Yakutsk (60.03°N, 129.73°E), 8– 25.08.1927, Moskvin, 2♂, 1♀ ; Olyokminsk Distr. , Biryuk R. near mouth of Melichan R. (60.5°N, 119.4°E), 13– 14.07.2008, A. Ovchinnikov, 1♂, 1♀ (all ZIN).

The above outlined geographical distribution of the subspecies explains why only the subspecies with dark frontal spots was report- ed for Chinese fauna ( Li & Yang 2017): few S. spinipes specimens examined by Chinese colleagues were from Xinjiang (90– 100°E) or Shaanxi (105– 110°E) provinces, these localities are to the west of line 119– 129°E .

The dark frontal spots are used as a diagnostic character; for example, the presence of these spots (together with the structure of the surstyli) distinguishes Sepedon ferruginosa from S. senex . In our opinion, the absence of the dark frontal spots as the only diagnostic character is not enough for description of a new species, but together with a clear distributional trend it is well suitable for a subspecies level. It is also practically useful because the Far Eastern S. spinipes flavifrons subsp. nov. is sympatric with a similar S. neanias , but the absence of frontal spots allows to distinguish these species at the first glance.