Neozavrelia nadezhdae, 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 : 272-278

Neozavrelia nadezhdae sp. nov.

( Figs 60–76 )

zoobank.org:act: 0DB662F6-6070-4AA8-8D96-72C783683A7A

Type material. Holotype: male, RUSSIA, KHABAROVSK TERRITORY, Bolshekhekhtsyrsky Reserve, Polovinka River , 21.v.2015, leg. N. Yavorskaya ; Paratypes: 5 males, same data, 21.v.2015, leg. N. Yavorskaya ; 6 mature chrysalis male, KAMCHATKA TERRITORY, Ust-Bolsheretsky District, Kurilskoye Lake , 10.ix.1996, leg. E. Makarchenko ; 1 pupa, same data, Oladochny stream, 10.ix.1996, leg. E. Makarchenko.

Derivatio nominis. Named after research assistant Nadezhda Yavorskaya, who collected the material.

Diagnosis. Male: darkly coloured species, with wing 1.8–1.9 mm long and AR 0.51–1.13; ultimate flagellomere 280–480 μm. Length of 2–4 flagellomeres of maxillary palpomeres 424–480 μm; 2 nd palpomere parallel-sided. R with 13–26, R 1 with 4–14, R 4+5 with 5–14, M 1+2 with 20–40, M 3+4 with 15–24, Cu 1 with 2–14 and An with 0–25 setae. LR PI 1.17–1.48. Basitarsus of mid leg with 1–5 sensilla chaetica. Mid tibia with 2 spurs. Anterior margin of tergite IX straight with developed lateral lobes. The anal point stout, parallel-sided, rounded apically, dorsally cover with several small spinulae. Superior volsella oval-shaped, bearing 3–4 strong apical and 6–11 fine dorsal setae, microtrichia absent. Stem straight and parallel-sided, 27–44 μm long.

Pupa: thoracic horn elongated oval or oval, 68–109 μm long, without spines; base of thoracic small, rounded, diameter 7 μm. Abdomen 2.4–2.5 mm long; hook row with 110–160 spines; tergites II–III with band of pale shagreen in the anterolateral corners; tergite VII with poorly developed shagreen in the anteriolateral corners, sometimes absent; anal comb with dark 5–10 apical and 14–23 dorsal tooth; anal lobe with dark strong spines on posterior third and 11–14 brown lamelliform setae; conjunctives of segments without setae.

Description. Adult male (n=9). Total length 2.4 mm; wing length 1.80–1.88 mm. Total length/wing length 1.2.

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, legs brown.

Head ( Figs 65–66 ). Frontal tubercles reduced in the form of small spots 3–7 μm in diameter, situated on swellings of frontal lobes or absent. Temporal setae 13–19. Clypeus with 15–19 setae. Antenna with 10 flagellomeres, 824–1056 μm long; ultimate flagellomere 280–480 μm. AR 0.51–1.13. Maxillary palpomeres 2–4 combined 424– 480 μm long, their individual lengths (in μm): 40–56: 104–120: 112–120: 160–84. Antenna length/palp length 1.91–2.17.

Thorax. Acrostichals 10–16, dorsocentrals 7–12, prealars 1. Scutellum with 9–12 setae.

Wing width 0.61 mm. VR 1.18. R with 13–26, R 1 with 4–14, R 4+5 with 5–15, M 1+2 with 20–40, M 3+4 with 15–24, Cu 1 with 2–14, An with 0–25 setae. Cell r 2+3, r 4+5, m 1+2, m 3+4, an with setae. Brachiolum with 1 seta.

Legs (see Table 8). Apical curved tibial spur of fore leg 44–48 μm long. Combs of mid and hind tibiae separated; each comb bears straight or slightly curved spur, 34–41 μm long. Basitarsus of mid leg with 1–5 sensilla chaetica.

Hypopygium ( Figs 60–61 , 67–70 ). Anal tergite with V-shaped bands and posterolateral lobes 10–24 μm long in dorsal view, а dark brown spike in the posterolateral corners; anterior margin straight. The anal point stout, parallel-sided, rounded apically, dorsally cover with several small spinulae and bearing 6–11 lateral setae on each side of anal point, 44–51 μm long and 24 μm wide on dorsal view; 58 μm long and 24 μm wide on lateral view. Gonocoxite 126–153 μm long, along the inner margin with 4–7 setae. The width of the transverse sternapodema 75–82 µm. Superior volsella oval-shaped (51–71 μm long, 17–31 μm wide), bearing 3–4 strong apical and 6–9 fine dorsal setae, microtrichia absent. Digitus 34–37 μm long and 10–14 μm wide. Stem of median volsella straight and parallel-sided, 27–44 μm long, bearing slender lamelliform setae; total length of median volsella 68–78 μm. Inferior volsella curved and rounded apically, 119–126 μm long, with 14–17 setae. Gonostylus straight, 102–136 μm long and expanded at about median (48–51 μm). HR 1.13–1.43.

Pupa (n=6, males).

Cephalothorax ( Figs 71–73 ). Cephalic tubercles weakly developed, 10 μm long and 14 μm wide, frontal setae 85 μm long. Thoracic horn short, elongated oval or oval, 68–109 μm long, 27–41 μm maximal wide, without spines; base of thoracic small, rounded, diameter 7 μm. Antepronotals 2 (1 median 136 μm long and 1 lateral 51–85 μm long). Precorneals 3 (1st 119–170 μm long, 2nd 119–163 μm long, 3rd 85–119 μm long). Dorsocentrals 4 (1 st pair 68–78 μm long; 2 nd pair 85–92 μm long); distance between Dc2 and Dc3 238–272 μm. Prealar tubercles rounded. Wing sheath usually with a well-developed “nose”.

Abdomen 2.4–2.5 mm long ( Figs 74–76 ). Hook row 379–440 μm long with 110–160 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): 85–112: 109–119: 136–153: 126–153: 136–204. Tergites II–III with band of pale shagreen in the anterolateral corners. Tergite VII with poorly developed shagreen in the anteriolateral corners, sometimes absent. Tergites VIII–IX with a pair of pale shagreen in proximal part. Comb of segment VIII 68–85 μm wide, with dark 5–10 apical and 14–23 dorsal tooth.Anal segment 122–143 μm long and 119–137 μm wide, each anal lobe with dark strong spines on posterior third and 11–14 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.

Larva unknown.

Remarks. The males collected on the Kurilskoye Lake and removed from mature pupae were not yet matured. Therefore, body parameters and indices may be unreliable (see Table 9). The males of N. nadezhdae sp. nov. are distinguished by the following features: inferior volsella reaches 2/3 of the length of the gonostylus, anterior margin of tergite IX straight, superior volsella without microtrichia ( Table 6).

Pupa of N. nadezhdae sp. nov. differs from all known species of this genus in the oval or elongated-oval shape of the thoracic horn and in the combination of morphometric characters shown in Table 10.

Distribution. Russian Far East (Khabarovsk and Kamchatka Territory).

Figures

FIGURES 60–64. Details of the structure of the male of Neozavrelia nadezhdae sp. nov. 60—total view of hypopygium; 61—lateral view of hypopygium; 62–64—thoracic horn. Scale bar 50 μm.

FIGURES 65–70. The male of Neozavrelia nadezhdae sp. nov. 65—head and maxillar palp; 66—antenna; 67–69—total view of hypopygium. Scale bar 50 μm.

FIGURES 71–76. Details of the structure of pupa of Neozavrelia nadezhdae sp. nov. 71—frontal apotome; 72—thorax; 73— thoracic horn and precorneals; 74—tergites II–III; 75—tergites IV–V; 76—anal combs and tergite IX. Scale bar 50 μm.