Neozavrelia kedrovaya, Orel, 2021

Orel, Oksana V., 2021, Revision of the genus Neozavrelia Goetghebuer, Thienemann, 1941 (Diptera Chironomidae) from Eastern Siberia and the Russian Far East, with the description of new species, Zootaxa 4938 (3), pp. 251-297 : 257-264

Neozavrelia kedrovaya sp. nov.

( Figs 9–38 )

zoobank.org:act: 80FC98D6-378E-4833-A034-6C9E69693F0A

Type material. Holotype: male, RUSSIA, PRIMORYE TERRITORY, Khasansky district , Kedrovaya River, 6– 7.vi.2000, leg. E. Makarchenko. Paratypes: 7 males, same data, 20.vi.2007, leg. E. Makarchenko ; 6 males, 5 pupae (1 pupa with larval exuvium), 3 larvae, same data, 2–3.viii.2016, leg. M. Astakhov ; 3 males, Lozovsky district, Partizanskaya River basin, Lozovy stream, 29.v.2004 , leg. T. Vshivkova ; 30 males, JEWISH AUTONOMOUS OBLAST, Amur River basin, Right Khingan River , 31.vii. 2003 , leg. O. Orel; 1 mature chrysalis male, 1 prepupae, CHITA REGION, Kadalinka River , 10.vi.2007 , leg. T. Tiunova .

Derivatio nominis. From the type locality Kedrovay River.

Diagnosis. Male: darkly coloured species, with wing 1.8–2.4 mm long and AR 0.79–1.15; ultimate flagellomere 408–600 μm. Length of 2–4 flagellomeres of maxillary palpomeres 504–624 μm. R with 17–29, R 1 with 8–14, R 4+5 with 12–25, M 1+2 with 16–50, M 3+4 with 3–16, Cu 1 with 0–11 setae, An with 0–17 setae. LR PI 1.3–1.5. Basitarsus of mid leg with 2–5 sensilla chaetica. Combs of mid and hind tibiae with 2 spurs. Anterior margin of tergite IX triangular form with well developed lateral lobes. Anal point slender, with narrowed and strongly elongated tip. Superior volsella oval-shaped, bearing 3–4 strong apical and 6–12 fine dorsal setae, microtrichia present or absent (or invisible). Stem straight and parallel-sided, 34–48 μm long.

Pupa: сephalic tubercles weakly developed or absent; thoracic horn short, triangular form, 78 μm long, 61 μm maximal wide, without spines; base of thoracic small, rounded, diameter 7–17 μm. Abdomen 2.0– 2.4 mm long; hook row with 116–146 spines; tergites II–III with band of pale shagreen in the anterolateral corners; tergite VII without shagreen or c several spines in anterolateral part; anal comb with dark 10–12 apical and 16–20 dorsal tooth; conjunctives of segments without setae; anal lobes with dark strong spines on posterior third and 8–16 brown lamelliform setae on each.

Larva: head yellowish brown. Clypeus 20–24 μm long and 119–133 μm wide, with elongated anterolateral angles; sclerite 2 68–85 μm long and 102–122 μm wide (maximum). Total length of antenna 122–126 μm, length of each segment (in μm): 68; 24–27; 14; 10; 7. AR 1.18–1.25. Blade 58 μm long, reaches the middle of the 4th segment; seta of the basal segment of the antenna located near the middle; distance between the seta of the basal segment of the antenna and the ring organ 20–26 μm; Lauterborn organs are almost 2 times as long as 3–5 antennal segments. Mandible 153–170 μm long and 102–116 μm wide; with dark brown dorsal, apical and 2 inner teeth. The medial tooth is shorter and narrower than the first lateral teeth of the mentum; the second lateral teeth are located at the same level or slightly below the first lateral teeth.

Description. Adult male (n=15). Total length 2.5–3.0 mm; wing length 1.8–2.4 mm. Total length/wing length 1.3–1.4.

Colouration. Ground colour of thorax, scutellum, maxillary palpomeres and abdomen yellowish brown; halters yellowish; antenna, scutal stripes, median band on distal half of mesonotum and postnotum dark brown; femora of fore leg yellowish with brown apical end, tibia yellowish with brown proximal and apical ends, ta 1+5 gradually darken towards the end or fore legs brown, mid and high legs yellowish or yellowish brown.

Head. Frontal tubercles absent or small 3.4 μm in diameter, situated on swellings of frontal lobes. Temporal setae 9–13. Clypeus with 13–21 setae. Antenna with 10 flagellomeres, 928–1132 μm long; ultimate flagellomere 408–600 μm. AR 0.79–1.15. Maxillary palpomeres 2–4 combined 504–624 μm long, their individual lengths (in μm): 40–64: 120–152: 120–152: 200–240 ( Fig. 9 ). Antenna length/palp length 1.73–2.00.

Thorax. Acrostichals 11–20, dorsocentrals 6–12, prealars 1–2. Scutellum with 6–13 setae.

Wing width 0.55–0.74 mm. VR 1.17–1.28. R with 17–29, R 1 with 8–14, R 4+5 with 12–25, M 1+2 with 16–50, M 3+4 with 3–16, Cu 1 with 0–11 setae, An with 0–17 setae. Cell r 2+3, r 4+5 with setae, m 3+4 with several setae. Brachiolum with 1–2 setae.

Legs (see Table 3). Apical curved tibial spur of fore leg 34–50 μm long. Combs of mid and hind tibiae separated; each comb bears straight or slightly curved spur, 27–44 μm (mid tibia) to 41–58 μm long (hind tibia). Basitarsus of mid leg with 2–5 sensilla chaetica.

Hypopygium ( Figs 10–21 , 23–28 ). Anal tergite with posterolateral lobes 17–34 μm long in dorsal view. The anal point stout, parallel-sided, rounded apically, dorsally cover with small spinulae and bearing 5–12 lateral setae on each side of anal point, 34–61 μm long and 17–24 μm wide on dorsal view; in lateral view anal point slightly bent, 44–58 μm long. Gonocoxite 146–170 μm long, along the inner margin with 3–7 setae. The width of the transverse sternapodema 44–68 µm. Superior volsella oval-shaped (48–58 μm long, 27–37 μm wide), bearing 3–4 strong apical and 6–12 fine dorsal setae, microtrichia present or absent (or invisible). Digitus 27–34 μm long μm wide. Stem of median volsella straight and parallel-sided, 34–48 μm long and 7–17 μm wide, bearing slender lamelliform setae; total length of median volsella 68–85 μm. Inferior volsella curved and rounded apically, 109–136 μm long, with 15–17 setae. Gonostylus straight and short, 102–129 μm long and expanded at about median (51–61 μm). HR 1.26–1.67.

Pupa (n=4, males).

Cephalothorax ( Figs 29–31 ). Cephalic tubercles weakly developed (10 μm long and 14 μm wide) or absent, frontal setae 85 μm long. Thoracic horn short, triangular form, 78 μm long, 61 μm maximal wide, without spines (n=1); base of thoracic small, rounded, diameter 7–17 μm. Antepronotals 2 (1 median 85–136 μm long and 1 lateral 51–102 μm long). Precorneals 3 (1 st 119–170 μm long, 2 nd 119–153 μm long, 3 rd 85–119 μm long). Dorsocentrals 4 (85 μm long); distance between Dc2 and Dc3 252–272 μm. Prealar tubercles rounded. Wing sheath usually with a well-developed “nose”.

Abdomen ( Figs 32–34 ) 2.0– 2.4 mm long. Hook row 336–344 μm long with 116–146 spines on tergite II. Tergites II–VI with a pair of longitudinal oval patches of dark spines on anterior part. Length longitudinal patches on tergites II–VI (in μm): 102–119: 119–136: 136–143: 136–143: 143–146. Tergites II–III with band of pale shagreen in the anterolateral corners. Tergites VIII–IX with a pair patches of pale shagreen in proximal part, sometimes tergite VIII with band of shagreen in proximal half. Tergite VII without shagreen or c several spines in anterolateral part. Comb of segment VIII 68–75 μm wide, with dark 10–12 apical and 16–20 dorsal tooth. Anal segment 102–119 μm long and 85–112 μm wide, each anal lobe with dark strong spines on posterior third and 8–16 brown lamelliform setae. Conjunctives of segments without setae. Segments II–VII with 3 simple L setae (on segment VII 2th L seta longest and stronger), VIII without seta, IX with 3 pair lamelliform setae.

Fourth instar larva (n=3). Total length 2–3 mm.

Head ( Figs 35–38 ) yellowish brown, length 0.3 mm, width 0.25 mm, cephalic index (W/L) 0.83. Clypeus 20–24 μm long and 119–133 μm wide; Sclerite 2 68–85 μm long and 102–122 μm wide (maximum). Distance between setae S 1 –S 1 78–88 μm (68 μm long), S 2 –S 2 129–136 μm (95–136 μm long), S 3 –S 3 71–82 μm (68 μm long), S 4 –S 4 92–109 μm (85 μm long), S 5 –S 5 102–112 μm. Antenna 122–126 μm, length of each segment (in μm): 68; 24–27; 14; 10; 7. AR 1.18–1.25. Maximal width of basal segment 20–24 μm; seta (41–51 μm long) of the basal segment located in the middle; distance between the seta of the basal segment of the antenna and the ring organ 20–26 μm; distance from ring organ to base of antenna 14 μm; ROR 1.5. Blade 58 μm long, reaches the middle of the 4th segment; accessory blade 17 μm; Lauterborn organs 58 μm long. S I comb-like, 20 μm long, S II 41 μm long, S III 34 μm long, S IVA 10 μm S IVB 7 μm long. Labral lamella 34 μm wide and with ~40 teeth. Premandible 88–92 μm long; premandibular seta simple 34 μm long. Mandible 153–170 μm long and 102–116 μm wide; with dark brown dorsal, apical and 2 inner teeth; apical tooth 14–20 μm wide and 17–20 μm high; two inner teeth 24–27 μm high. Seta subdentalis 34 μm long. Maxillary palp 17–24 μm long, 14–17 μm wide. Mentum 102–109 μm wide; median tooth rounded 10 μm wide, without a small accessory tooth; distances between first lateral teeth 34 μm; distance between second lateral teeth 58–61 μm. Ventromental plate 102–109 μm long and 41 μm wide. MVR 1.0.

Remarks. Morphometric characters of the males of N. kedrovaya sp. nov., collected from various watercourses in Eastern Siberia and the Russian Far East are similar to each other (see Table 4). There are slight variations in shape and length of gonostylus ( Figs 16–18 ), tergite IX in lateral view ( Figs 19–21 ). The width of the anal point can also vary in males from the same population ( Figs 11–12 ).

The males of N. kedrovaya sp. nov. are most similar in structure to hypopygium with N. kuzmichikha sp. nov., but differs in the following features: the lengths of the antenna (928–1132 μm) and maxillary palp (504–624 μm), wing chaetotoxia (R with 17–29, R 1 with 8–14, R 4+5 with 12–25, M 3+4 with 3–16, Cu 1 with 0–11 setae, An with 0–17 setae), and the presence of 2 spurs on the middle tibia (see Table 6). Whereas the males of N. kuzmichikha sp. nov. have an antenna length 864–880 μm, a maxillary palp length 416–440 μm, wing chaetotoxia (R with 11–15, R 1 with 1–2, R 4+5 with 2, M 3+4, Cu 1 and An without setae), the presence of only one spur on the middle tibia (see Table 6).

The males of N. kedrovaya sp. nov. are also similar to N. minuta (Linevich) , but differ from the latter by the following features: wing length 1.8–2.4 mm, shorter antenna (928–1132 μm), R 1 with 8–14 setae, superior volsella without or with several microtrichia, gonostylus 102–1129 μm long. Whereas the males of N. minuta (Linevich) have wing length 2.6–2.7 mm, antenna about 1200 μm, R 1 with 0–4 setae, superior volsella dense covered with microtrichia, gonostylus 133–150 μm long (see Table 6).

Pupa of N. kedrovaya sp. nov. is well distinguished by the triangular shape of the thoracic horn and the combination of morphometric features, which are indicated in Table 10.

Up to the present time the larvae are known only for 4 Palearctic species, namely, N. cuneipennis (Edwards) , N. bernensis (Reiss) , N. luteola Goetgebuer and N. minuta (Linevich) . The larva of N. kedrovaya sp. nov. can be distinguished by the following combination of features: Lauterborn organs are 2 times as long as 3–5 segments of the antenna, length of 4–5 segments of antenna equal to the length of 3rd segment, blade of antenna reaches middle of 4th segment; distance between the seta of the basal segment of the antenna and the ring organ 20–26 μm; distance from ring organ to base of antenna 14 μm, AR 1.18–1.25, the middle tooth of the mentum is shorter and narrower than the first lateral teeth, the second lateral ones are located at the same level or just below the first lateral teeth. Anna Andreevna Linevich (1963) describes in great detail the life cycle of N. minuta , but, unfortunately, does not provide a morphological description of the main life stages of this species. Therefore, it is not possible to compare this species with other species of the genus Neozavrelia .

Distribution. Russian Far East (Primorye Territory, Jewish Autonomous Oblast), East Siberia (Chita Region).

Figures

FIGURES 9–22. Details of the structure of the male of Neozavrelia kedrovaya sp. nov. 9—maxilar palp; 10—total view of hypopygium; 11, 12—anal point; 13—superior volsella; 16–18—gonostylus and inferior volsella; 19–21—tergite IX, lateral view; 22—thoracic horn. Scale bar 50 μm.

FIGURES 23–28. The male of Neozavrelia kedrovaya sp. nov. 23—head; 10—antenna; 25, 26— total view of hypopygium; 27—hypopygium, lateral view; 18—apical part of wing. Scale bar 50 μm.

FIGURES 29–34. Details of the structure of pupa of Neozavrelia kedrovaya sp. nov. 29—frontal apotome; 30—thorax; 31— thoracic horn and precorneals; 32—tergites II–V; 33—tergites VII–IX; 34—anal combs and tergite IX. Scale bar 50 μm.

FIGURES 35–38. Details of the structure of larva of Neozavrelia kedrovaya sp. nov. 35—labrum; 36—antenna; 37—mandible; 38—mentum and ventromental plates. Scale bar 50 μm.