Spilogona latizygoma, Sorokina, 2025

Spilogona latizygoma sp. nov.

Figs 3 A–I View FIGURE 3

Spilogona tendipes (Malloch, 1920) View in CoL ; Sorokina & Michelsen 2014: 516 View Cited Treatment . Wrangel Island. Misidentification.

Type material: Holotype ♂, RUSSIA, Wrangel Island : Somnitil’naya Bay , valley of the River Somnitil’naya, Mineeva Mts, 150 м, on flowers of Potentilla emarginata , 19.vii.1966, leg. K. Gorodkov ( ZISP).

Paratypes: RUSSIA, Wrangel Island : 1♀, Somnitil’naya Bay , valley of the River Somnitil’naya, south of island, Mineeva Mts, 250 м, 22.vii.1966, leg. K. Gorodkov ( ZISP) ; 2♀♀, Somnitil’naya Bay , south of island, 22, 26.vii.1966, leg. K. Gorodkov ( SZMN) ; 2♂♂ 4♀♀, middle part of the River Neozhidannaya , 71°01’N 179°09’W, yellow pan traps, 12–16.vii.2016, leg. L. Volkova ( SZMN, 1♂ — BUIC-DIP1761 , 1♀ — BUIC-DIP1762 ) GoogleMaps ; 1♀, middle part of the River Neozhidannaya , valley of river, 71°01’N 179°08’W, yellow pan traps, 10.vi.–27.vii.2016, leg. L. Khruleva ( SZMN) GoogleMaps ; 1♀, middle part of the River Neozhidannaya , 71°01’N 179°09’W, yellow pan traps, 8, 9.vii.2019, leg. L. Khruleva ( SZMN) GoogleMaps ; 2♂♂ 1♀, Tundrovii Mt. , 71°16’N 179°53’W, yellow pan traps, 8–10.vii.2018, leg. U. Babii ( SZMN) GoogleMaps ; 2♀♀, Tundrovii Mt. , 71°18’N 179°48’W, yellow pan traps, 7–11.vii.2019, leg. U. Babii & O. Khruleva ( SZMN) GoogleMaps ; 1♀, middle part of the River Mamontovaya , 71°10’N 179°45’W, yellow pan traps, 2–7.vii.2015, leg. O. Khruleva ( SZMN, BUIC-DIP1763 ) GoogleMaps ; 1♀, upper reaches of the River Neizvestnaya , 71º13’N 170º19’W, yellow pan traps, 4–11.vii.2015, leg. O. Khruleva ( SZMN) GoogleMaps .

Etymology. The species name is based on the Latin words “latus” and “zygoma” meaning “wide cheekbones”, because the parafacial is very broad.

Diagnosis. The new species is very similar to Spilogona tendipes (Malloch, 1920) because of its large size, covering of dense grey dusting with a bluish or greenish tinge and having paired dark marks visible on abdomen, a projecting lower face, small eyes, very broad parafacial, long and slender haustellum with a shiny prementum and slender and elongate labella, 4 pairs of postsutural dorsocentral setae, hind tarsus with a v seta near base, and hypoproct with recurrent spines. But the new species differs substantially from Spilogona tendipes by the absence of ventral seta on mid tibia, distinct long pv in basal half of hind femur, numerous hair-like av setae in basal half of all femora, long ground-setulae of scutum, long setae on sternites 3–5, more greenish tinge of body, almost inconspicuous hairs on eye, and the male terminalia.

Description: Male: body 5.3–5.7 mm, wing 4.8–5.0 mm.

Head: Ground-colour black. Frons, fronto-orbital plate, gena and parafacial shining silvery-grey or silverybrown, with dark reflections when viewed in profile. In lateral view, facial edge projecting beyond level of profrons ( Fig. 3A View FIGURE 3 ). Eye small, bare or with very sparse and inconspicuous hairs. Fronto-orbital plates separated by a wide frontal vitta. Distance between eye margins on upper part of frons about as wide as ocellar triangle ( Fig. 3B View FIGURE 3 ). Frontal triangle extending to middle of frons. Frons with 12–14 pairs of strong frontal setae. Parafacial at level of base of antenna 1.5–2 times width of postpedicel, not narrowing below. Height of gena about 1/3–1/4 of height of eye and 1.5–2 times width of postpedicel. Antenna black, postpedicel approximately 1.5 times as long as wide. Arista black, bare, thickened in basal half. Palpus black. Proboscis long, slender, prementum shining. Labella slender and elongate, crocheted relative to the proboscis.

Thorax: Ground-colour black, densely grey dusted with a bluish or greenish tinge, with two brown indistinct presutural longitudinal stripes when viewed from in front. Ground-setulae of scutum relatively long, hair-like. Presutural acr setae in 3–4 uneven rows, 2+4 dc setae. Notopleuron bare, or with individual hairs. Anepisternum with 2–3 interspatial setae. Katepisternal setae 1+1. Scutellum grey dusted, with downwardly-directed preapical setulae on upper border of declivities.

Wing: Light brownish tinged, with dark base. Costa without spinules or costal spine. Calypters whitish, with light yellow margins. Haltere brown with blackish knob.

Legs: Ground colour black, grey dusted. Fore tibia with 2–4 p setae. Fore femur with numerous long hair-like setae on posterior surface, with a row of short hair-like av setae. Mid femur with a row of long pv setae and with a row of short hair-like av-v setae, with 2 pd–p preapical setae. Mid tibia with 2–3 ad and 3 pd setae, without any v setae. Hind femur with a row of long av setae becoming shorter on basal third, with a row of long pv setae in basal half, with numerous long hair like setae on basal part of posterior surface. Hind tibia with 3–5 av, 4–6 ad, with an uneven row of long pd-p setae in middle part, without pv setae. First tarsomere of hind tarsus with strong v seta near base.

Abdomen: Black with dense bluish-grey dust, conical. Tergites 1+2–4 with large brown triangular marks separated by a brown median stripe, sometimes fused, tergite 5 with a brown median stripe. Sternite 1 bare or with individual hairs, sternites 2–5 with numerous long setae, especially sternite 5, sternite 5 large, longer then sternite 4, with a deep median notch, and a pointed caudal margin ( Figs 3E, I View FIGURE 3 ).

Terminalia: In lateral view cerci wide in proximal half and narrow, rod-shaped in distal half, curved; surstylus rounded at apex, with a notch in ventral margin, shorter than cerci; epandrium large, hemispherical; hypandrium 2 times shorter then epandrium, with a wavy ventral margin ( Figs 3D, G View FIGURE 3 ). Cercal plate oval with two apical prolongations ( Fig. 3H View FIGURE 3 ).

Female: body 6.2–7.3 mm, wing 5.7–6.7 mm.

Similar to male but differing as follows:

Head: Frons, fronto-orbital plate, gena and parafacial densely brown dusted, contrasting with the greenish-bluish-grey occiput ( Fig. 3C View FIGURE 3 ). Frontal vitta matt grey, contrasting with brown fronto-orbital plate and frontal triangle when viewed from above. Width of frontal vitta 2–2.3 times width of a fronto-orbital plate. Frontal triangle brown dusted, extending to lunule. Fronto-orbital plate with an uneven row of frontal and orbital setae. Parafacial at level of base of antenna 2–2.3 times width of postpedicel. Height of gena about 1/2–1/3 of height of eye.

Thorax: Colour lighter, with greenish-bluish-grey dust. Scutum with 3 brown longitudinal stripes, sometimes indistinct, not extending to scutellum.

Abdomen: Postgenital plate with weak individual spinules.

Distribution. PALAEARCTIC: Arctic Russia (Wrangel Island).

DNA barcode. BOLD BIN: BOLD:ADZ7218. See Table 1 for GenBank accession numbers.

Remarks. Spilogona latizygoma morphological is very similar to Spilogona tendipes . But based on DNA barcodes, these species are genetically different; the p-distance between them is 3.36%. The intraspecific distance of Spilogona latizygoma specimens ranges from 0.0% to 0.16%.