Diamesa parancysta Serra-Tosio

Makarchenko, Eugenyi A. & Semenchenko, Alexander A., 2023, Morphological redescription and DNA barcoding of Diamesa parancysta Serra-Tosio (Diptera: Chironomidae: Diamesinae), Zootaxa 5357 (1), pp. 144-150 : 145-147

Diamesa parancysta Serra-Tosio

( Figs 1–17 )

Diamesa parancysta Serra-Tosio, 1983: 15 ; Willassen et al. 2005: 71; Ashe & O’Connor 2009: 282; Krasheninnirkov 2009: 66, 2011: 248; Kang et al. 2017: 120; Makarchenko et al. 2022a: 80.

Diamesa corrupta Makarchenko, 1988: 54 .

Diamesa sp. Ge, Xia, Wang, Zhang, Ma & Zhou, 2021: 6. Syn. nov.

Diamesa sp. XJC Webb, Cole & Simmons, 2022: 138. Syn. nov.

Material examined. Russia: 1 adult male, Irkutsk region, Upper Angara River, Padun village , 19.IV.1930, leg. Chekanovsky ; 2 adult males, Krasnoyarsk Territory, Ermakovsky District, Kulumys Ridge , Lake Oiskoe , alt. 1400 m a.s.l., 23.VII.2014, leg. E. Borisova ; 1 adult male, Republic of Khakassia, Abakan City, valley of the Abakan River , poplar forest, ultraviolet lamp, alt. 245 m a.s.l., 2–3.IV.2020, N 53.71375, E 91.505444, leg. S. Dragan , 2 adult males the same data, except 6.IV.2020, leg. S. Dragan ; 2 adult males, Perm Territory, Suksunsky District, Koshelevo Village , mouth of Suksunchik River , alt. 138 m a.s.l., 27.III.2014, N 57.156083, E 57.421111, leg. A. Krasheninnikov ; 2 adult males, Magadan Region, Olskyi District, 137 km of Kolymskaya Road, Ola River , 1. V.2015, N 60.412194, E 151.514564, leg. Е. Khamenkova. Kazakhstan: 2 adult males, 2 pupae (males), 2 larvae, East Kazakhstan region, Katon-Karagai District, Sarymsaqty Mountains ( Kazakh Mountain Altai ), Arasan River , about 0.7 km below of Bolshoe Rakhmanovskoye Lake , alt. 1790–1809 m a.s.l., 5–6.VII.2018, N 49.535983, E 86.500633, leg. D. Palatov. Mongolia: 1 adult male, Govi-Altay Aymag, Uliastein Gol River at the confluence of Baga Gol River , light trap, alt. 1989 m a.s.l., 22.IX.2019, N 45.4846, E 94.277067, leg. D. Palatov.

Adult male (n = 6). Total length 4.5–5.2 mm. Total length/wing length 1.06–1.2.

Coloration. Dark brown to brown. Wings grayish, venation brownish.

Head. Eyes hairy, reniform. Temporal setae including 8–10 preoculars, 7–14 verticals, 9–15 postorbitals. Clypeus with 12–16 setae. Antenna with 13 flagellomeres and developed plume of seta; terminal flagellomere with 1 subapical setae, 24–50 μm long; AR 1.69–2.46. Palpomere length (μm): 44–77, 88–134, 116–202, 108–190, 172–279. Palpomere 3 in distal part with sensilla capitata with diameter 14–16 μm. Head width/palpal length 1.24–1.45.

Thorax. Antepronotum with 5–15 ventrolateral setae. Dorsocentrals 7–14, prealars 7–13. Scutellum with ca 33–50 setae.

Wing. Length 4.2–4.9 mm, width 1.2 mm. Anal lobe rounded, slightly protrudring. Squama with 36–53 setae in 1–2 rows. R and R 1 with 23–28 setae, R 4+5 with 4–14 setae. RM /MCu 2.67. Costa extension 114 μm long.

Legs. Spur of front tibia 76–89 µm long. Spurs of mid tibia 60–88 and 52–73 µm long. Spurs of hind tibia 92–112 and 56–77 µm long. Hind tibial comb with 18 – 22 setae. Length (μm) and proportions of leg segments are as in Table 1 .

Hypopygium ( Figs. 1–7 ). Tergite IX with distinct tergal bands, 9–19 setae, 20–28 µm long from one side and anal point, 240–366 µm long which has terminal dorsal keel and apical setiform sensilla ( Figs. 1– 2 ). Laterosternite IX with 4–10 setae, 44–72 µm long. Transverse sternapodeme straight or sometimes little concave, with strongly projecting anterolateral corners ( Figs. 1, 6 ), 168–223 μm long. Gonocoxite 340–372 µm long, with large inferior volsella, broad and prominent basal plate ( Figs. 1, 5–7 ). Basimedial setae cluster well developed, with 15–23 long yellowish setae, 160–231 µm long ( Fig. 4 ). Gonostylus gently curved and relatively broad, 208–240 µm long and 36–52 µm wide, with megaseta, 12 µm long and apical tooth, 10 µm long ( Figs. 3, 5–7 ). HR=1.44–1.82.

Pupa (n=2). Total length 5.4–5.5 mm. Сephalothorax dark brown, abdomen yellowish brown. Coloration brownish. Exuviae yellow.

Cephalothorax. Frontal apotome with 2 setae 284–288 μm long. Thorax wrinkled, in anterodorsal and lateral parts granulated. Thoracic horn 390–400 μm long, filiform, with small spinules at the top, yellow except for brown basal part. Precorneal setae lengths (μm): Pc 1 —110–164, Pc 2 —224–228, Pc 3 —84–88 ( Fig. 8 ). Antepronotum with 2 median seta, 120–128 μm long and 1 lateral antepronotals, 80 μm long. Mesonotum with 2 dorsocentrals: Dc 1 strong, 140–148 μm long, Dc 2 hair-like, 24–28 μm long.

Abdomen. Tergite I with delicate shagreen only in anterolateral angles. Tergites II–VII with shagreen in anterior third or half, tergite VIII almost all with shagreen. Sternites I–II without shagreen, sternites III–VIII with rare shagreen and IX without shagreen. Tergite I and sternites I–II without posterior transverse row of spines. Tergites II—VIII with posterior transverse row spines, number of these spines on tergites respectively—9: 8–9: 9: 10: 9: 8: 8–9 ( Figs. 9–11 ). Number of posterior transverse row spines of sternites III–VIII respectively—9: 7–8: 8: 7–8: 7–8: 89 ( Figs. 9–11 ). Segment I with 1 pair of lateral setae; segments II–VIII with 3 pairs of strong brown lateral setae, 140–148 μm long (L 1 –L 3) and 1 pair of hair-like setae, 80–84 μm long (L 4). Segments II –VIII with spine-like process on posterolateral corner. Anal lobe with 3 yellow anal macrosetae, 300–336 μm long, slightly curved in distal part and pointed. Male genital sac little extended beyond anal lobe ( Fig. 12 ).

Fourth instar larva (n = 2). Total length 7.3–7.4 mm. Head capsule 420–460 µm long; dark brown to black, postoccipital margin black and wide; abdomen brownish. S I short, seta-like; S II and S III simple, hair-like ( Fig. 17 ). Labral lamellae consisting of 5 lobes. Premandible broad, apically with 6 teeth ( Fig. 16 ). Antenna with 5 segments, length of antennal segments (µm): 72, 18, 8, 5, 4. Lauterborn organs small; style reaches base of fourth segment; longest branch of antennal blade reaches the apex of the fourth segment; ring organ ca 7 µm diameter located in basal quarter of first segment ( Fig. 15 ); AR 2.0–2.1. Mandible dark brown to black, with apical tooth and 4 inner teeth; apical tooth narrow, twice as long as first inner tooth; seta subdentalis minute; seta interna with 24–26 simple branches ( Fig. 14 ). Mentum with 1 median and 9 pairs of lateral teeth; median tooth about the same size as the first lateral teeth or little wider and together with them slightly lighter than the rest of the lateral teeth; ventromental plate small ( Fig. 13 ). Procercus dark brown, in the form of incompletely sclerotized ring, bearing 4 dark brown strong anal setae, 276–296 µm long and 1 hair-like lateral seta which is on the body, 48–56 µm long. Posterior parapods 656–689 µm long, in 1.3–1.4 times as long as last body segment. Dorsal and ventral pairs of anal tubulus 246 µm long.

Remarks. Serra-Tosio (1983) brought the adult male of D. parancysta closer to the North American Diamesa nivoriunda group of species ( Hansen & Cook 1976) and, in particular, to D. ancysta Roback. Our data on morphology and DNA barcoding indicate a close relationship of this species also to the East Palaearctic species D. vernalis and D. dactyloidea . The male D. parancysta is well separated from the listed species in the structure of the hypopygium, namely in the shape of gonostylus and inferior volsellae, number of basimedial setae. Males of the studied populations fit well into the description of the species. The highest AR (2.12–2.46) are in specimens from the Urals and Khakassia, the lowest are in males from Mongolia (AR 1.49–1.79). The maximum LR value (0.80) is in specimens from the Krasnoyarsk Territory, the minimum (LR 0.66) is in males from the Upper Angara River. Pupa is very similar to D. tsutsuii while larva to D. tsutsuii and D. arctica (Bohemann) but larvae of these species can be good distinguished by mentum. Mentum of D. parancysta with 1 median and 9 pairs of lateral teeth; median tooth about the same size as the first lateral teeth or little wider and together with them slightly lighter than the rest of the lateral teeth. Mentum of D. tsutsuii with 1 median and 10 pairs of lateral teeth. Mentum of D. arctica with 1 median and 9 pairs of lateral teeth, the middle of the mentum is straight, the median tooth and the first 3 pairs of lateral teeth are almost the same size and higher than the lateral ones.

Distribution. Known from Norway, Ural Region, Mongolia, Altai Mountains, Baikal Lake basin, Khakassia, China, South Korea, Alaska ( Hayford 2005; Ashe & O’Connor 2009; Krasheninnirkov 2009; Kang et al. 2017; Ge et al. 2021; Makarchenko et al. 2022a; Webb et al. 2022).

Figures

FIGURES 1–7.Adult male of Diamesa parancysta Serra-Tosio from Upper Angara River (1–4), Magadan Region (5), Khakassia (6) and Kazakh Mountain Altai (7). 1, 5, 6–7, hypopygium in dorsal view; 2, apical part of anal point; 3, apex of gonostylus; 4, gonocoxite and gonostylus in ventral view.

FIGURES 8–17. Pupa (8–12) and larva (13–17) of Diamesa parancysta Serra-Tosio. 8, thoracic horn and precorneals; 9, segments IV–V, lateral view; 10, segments VI–VII, lateral view; 11, segments VII–VIII, lateral view; 12, segment VIII and anal segment, lateral view; 13, mentum; 14, mandible; 15, antenna; 16, premandible; 17, S-setae of labrum. Scale bars: Fig. 14—50 μm; Figs. 15–17—20 μm.