Polypedilum

Orel, Oksana V., 2018, New species of the non-biting midges of Tribe Chironomini (Dptera, Chironomidae) from the Bolshekhekhtsyrsky Reserve (Russia, Khabarovsk Territory), Zootaxa 4461 (2), pp. 269-276 : 270

Polypedilum (s. str.) odyrensis sp.n.

( Figs 1–4 , 11–15 )

Type material. Holotype: 1 male, Russia, Khabarovsk Territory, Bolshekhekhtsyrsky Nature Reserve, basin of the Chirka River, Odyr River , 19.VI.2016, leg. N.M. Yavorskaya . Paratype: 1 male, same data, 19.VI.2016, leg. N.M. Yavorskaya.

Derivatio nominis. The species name is from the type locality, Odyr River, and the Latin suffix— ensis denoting locality.

Diagnostic characters. The new species has the following combination of characters: wing length 1.7–1.8 mm, without spots and setae on the surface; thorax and abdomen brown, halters and legs yellowish; AR 0.93–1.04; humerals 3–4; anal point long and narrow; superior volsella straight, bearing 1 lateral seta in apical half and 2–3 basal setae and cover with rare microtrichia; gonostylus massive, short and wide, slightly expanded in the apical third; HR 0.97–1.2.

Description. Adult male (n=2). Total length 2.8–3.0 mm. Wing length 1.7–1.8 mm. Total length/wing length 1.6–1.7.

Coloration is brown. Antenna, thorax and abdomen brown; halters and legs yellowish.

Head. Head width 400–432 µm. Frontal tubercles absent. Antenna 880–928 µm long. Ultimate flagellomere 424–472 µm long. AR 0.93–1.04. Verticals 10–11. Clypeus with 15–17 setae. Lengths of last 4 palpomeres (in µm) of maxillary palp: 44–51; 99–105; 126–133; 176–200.

Thorax. Antepronotals 0, acrostichals 16–17, humerals 3–4, dorsocentrals 13–16, prealars 4–6, supraalars 0. Scutellum with 16–18 setae.

Wing. Width 0.53–0.57 mm. Veins R with 25–28, R 1 15–17 setae, R4+5 with 34 setae. Squama with 10 setae; brachiolum with 1–2 setae. VR 1.23.

Legs. Scale of fore tibia elongated or with apical spur 22 µm long ( Figs 11–12 ). Spurs of middle and hind tibia 44 µm long. Lengths and proportions of legs as in Table 1.

Hypopygium ( Figs 1–4 , 13–15 ). Tergite IX with 13–17 median setae. Laterosternite IX with 3–5 setae. Anal point long and narrow (92 µm and 10 µm respectively), with 10–15 lateral setae at the base. Gonocoxite 102–109 µm long, with 6 inner setae. Phallapodeme 92 µm. Transverse sternapodeme 51–68 µm long. Superior volsella straight and narrow 65–75 µm long, apical part 51–61 µm long, the base height 10 µm and width 20–24 µm, with 2–3 basal setae and cover with rare microtrichia, and 1 lateral seta located in apical half; RSVo 0.63–0.73. Inferior volsella 119–122 µm long, with 11–14 setae. Gonostylus short and wide (85–112 µm and 61 µm respectively), slightly expanded in the apical third, the inner margin with 1 short apical seta and 3–4 longest subapical setae. HR 0.97–1.2.

Female, pupa and larva unknown.

Remarks. Polypedilum (s. str.) odyrensis sp.n. is unique in Polypedilum genus in the shape of the gonostylus. This type of gonostylus is often seen in Chironomus and Kiefferulus , also sometimes in Axarus , Lipiniella , Endochironomus complex and Stictochironmus complex. Thirteen-segmented antenna, the antepronotal lobes narrowed dorsally and medially narrowly separated, the combs of mid and hind tibia separates and one of the combs with a long spur, tergite VIII tapered basally to testify the species is the member of genus Polypedilum . The adult males of P. (s. str.) odyrensis sp.n. are very different from all known species of the subgenus Polypedilum by the original structure of gonostylus—massive, wide and short.

Distribution. Known only from the typical habitat—Bolshekhekhtsirsky Nature Reserve (Khabarovsk Territory).

Figures

FIGURES 1–5. Details of hypopygium structure of the male of Polypedilum (s. str.) odyrensis sp.n. (1–4) and Polypedilum (s. str.) servatum sp.n. (5). 1, 5—dorsal view of hypopygium; 2—tergite IX and anal point in dorsal view; 3, 4—superior volsella in dorsal view. Scale bars 50 µm.

FIGURES 11–15. The male of Polypedilum (s. str.) odyrensis sp.n.11–12—apex of fore tibia; 13–14—hypopygium; 15— tergite IX and anal point. Scale bars 50 µm.