Neozavrelia tygda, 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 : 287-289

Neozavrelia tygda sp. nov.

( Figs 110–119 )

http://zoobank.org/NomenclaturalActs/ CF140665-0553-4724-9049-233692C6FBF3

Type material. Holotype: 1 male, RUSSIA, AMUR REGION, Zeya River Basin, Tygda River , 11.ix.2007, leg. T. Tiunova.

Derivatio nominis. From the type locality Tygda River.

Diagnosis. Wing 0.98 mm long. Frontal tubercles minute. AR 0.66. Tergite IX medially with microtrichia are located in the form of a mesh structure. The anal point triangular, dorsally with 9 short dark strong spinulae. Superior volsella elongated oval-shaped with ventral seta. Digitus reaches of the medial edge of the superior volsella.

Description. Adult male (n=1). Total length 1.65 mm; wing length 0.98 mm. Total length/wing length 1.68.

Colouration. Ground colour of thorax, maxillary palpomeres yellowish brown; halters yellowish; antenna, scutal stripes, median band on distal half of mesonotum, scutellum postnotum, legs and abdomen brown.

Head ( Figs 114–115 ). Frontal tubercles minute, 3 μm long and 4 μm wide. Temporal setae 7–8. Clypeus with 8 setae. Antenna with 13 flagellomeres, 540 μm long; ultimate flagellomere 215 μm. AR 0.66. Maxillary palpomeres 2–4 combined 255 μm long, their individual lengths (in μm): 30: 70: 65: 90. Antenna length/palp length 2.12; head width/palp length 1.25.

Thorax. Acrostichals 11, dorsocentrals 4–5, prealar 1. Scutellum with 4 setae.

Wing width 0.30 mm ( Figs 116–118 ). VR 1.33. R with 14, R 1 with 6, R 4+5 with 6, M 1+2 with 30, M 3+4 with 9, Cu 1 with 10, An with 8, Vf with 8 setae. Cell r 2+3, r 4+5, m 1+2, m 3+4 with setae. Brachiolum with 1 seta.

Legs (see Table 16). Apical curved tibial spur of fore leg 24 μm long. Combs of mid and hind tibiae separated; each comb bears straight or slightly curved spur, 14–16 μm (mid tibia) to 14–20 μm long (hind tibia). Basitarsus of mid leg without sensilla chaetica.

Hypopygium ( Figs 110–113 , 118–119 ). Anal tergite with H-shaped bands, between which microtrichia are located in the form of a mesh structure, and with 5–6 lateral setae, free-microtrichia areas present on the sides of anal tergite bands. The anal point (20 μm long and 20 μm wide in the base and 9 μm wide on the apex) broad, triangular rounded apically, dorsally cover with 9 strong spinulae (4–8 μm long) and bearing 2–3 lateral setae on each side of the anal point; microtrichia located between the anal tergite bands form a mesh pattern ( Fig. 111 ). Gonocoxite 90 μm long, along the inner margin with 3 setae. The width of the transverse sternapodema 50 µm. Phallopodema 88 μm long. Superior volsella elongated oval-shaped (40 μm long, 14 μm wide), bearing 2 median setae and 1 strong inner seta on a tubercle, and 5–6 fine dorsal setae, microtrichia absent ( Figs 112–113 ). Digitus 12 μm long, reaching of the medial edge of the superior volsella. Stem of the median volsella straight 28 μm long, bearing slender lamelliform setae; total length of the median volsella 40 μm. Inferior volsella 70 μm long, with 10–12 setae. Gonostylus straight, 60 μm long and expanded at about median 20 μm. HR 1.5.

Pupa and larva unknown.

Remarks. The male of Neozavrelia tygda sp. nov. is more similar to the N. oyabeparvulus ( Sasa et al., 1988) but differs from the latter by the presence of a reticulate structure of microtrichia on tergite IX and a triangular shape of the anal point (see Table 12).

Figures

FIGURES 110–113. Details of the structure of hypopygium the male of Neozavrelia tygda sp. nov. 110—total view of hypopygium, dorsal view; 111—tergite IX and anal point, dorsal view; 112, 113—superior volsella, ventral and dorsal view. Scale bar 50 μm.

FIGURES 114–119. The male of Neozavrelia tygda sp. nov. 114—head and maxillary palps; 115—antenna; 116–117—wing; 118–119—hypopygium. Scale bar 50 μm.