Pseudokiefferiella silinka Makarchenko et Semenchenko, 2023

Makarchenko, Eugenyi A. & Semenchenko, Alexander A., 2023, Two new chironomid species of the genus Pseudokiefferiella Zavřel (Diptera: Chironomidae: Diamesinae) from the Amur River basin of Russia, Zootaxa 5339 (5), pp. 481-491 : 487-489

Pseudokiefferiella silinka Makarchenko et Semenchenko , sp. nov.

http://zoobank.org/NomenclaturalActs/ D9D8264A-89D7-4D06-8933-D509CCB0A908

( Figs 19–25 )

Type material. Holotype: adult male, Russia: Khabarovsk Territory, Solnechnyi District, environs of Gornyi Village , Miao Chan Ridge , valley of the Levaya Silinka River , Amur River basin, 27.VII.2006, N 50.710861, E 136.365278, light trap, leg. E. Makarchenko.

Derivatio nominis. The species is named as silinka after the type locality in Levaya Silinka River of the Amur River basin. The name is a noun in apposition.

Description

Adult male (n = 2, except when otherwise stated). Total length 2.7–2.8 mm. Total length/wing length 1.16.

Coloration. Grayish brown. Head, thorax and abdomen with hypopygium grayish brown or brown. Legs brownish gray. Wings greyish.

Head. Eyes pubescent, slightly elongate dorsomedially. Temporal setae including 7–8 verticals and 12 postorbitals. Clypeus with 2 setae, 52–68 μm long. Antenna with 13 flagellomeres and well developed plume of setae; maximal length of these setae on flagellomeres 558 μm; terminal flagellomere with 1 subapical seta, 36 μm long; pedicel with 2 setae. AR 0.81. Palpomere length (μm): 32–40, 48–56, 88–108, 92–96, 132–160. Palpomere 3 in distal part with sensilla capitata with diameter 8 μm. Head width/palpal length 1.0.

Thorax. Antepronotum with 2–4 ventrolateral setae, 32–40 μm long. Dorsocentrals 7–10, 84–88 μm long, prealars 3–4, 72–80 μm long. Scutellum with 7–8 setae in 1 row.

Wing. Length 2.3–2.4 mm, width 0.64 mm. Anal lobe developed and rounded. Squama with 14 setae, 52–68 μm long. R and R 1 with 17 setae, R 4+5 with 5 setae in distal part. RM/MCu 2.5.

Legs. Spur of front tibia 40–60 µm long. Spurs of mid tibia 40–44 µm and 40 µm long. Spurs of hind tibia 56–60 µm and 40–44 µm long. Hind tibial comb with 14–15 setae. Length (μm) and proportions of leg segments are as in Table 2 .

Hypopygium ( Figs 19–25 ). Tergite IX with 12–14 setae, from one side, 28–40 µm long and with narrow, sharply pointed anal point, 68–80 µm long ( Figs 19, 21 ). Laterosternite IX with 5–8 setae, 60–72 µm long. Transverse sternopodeme consisting of a narrow arch 176 µm long, expanded in the middle ( Fig. 23 ). Aedeagal lobe wedge-shaped, 68 µm long ( Fig. 23 ). Gonocoxite 212 µm long, with basal plate in the form of two rounded or rounded triangular tubercles, the lower of which is covered with microtrichia and numerous long setae, the upper without microtrichia and only with 3–4 setae ( Fig. 22 ). Gonostylus narrow, 100–104 µm long, with long crista dorsalis; apex with short macroseta, 8–12 µm long ( Figs 24–25 ); HR 1.9–2.2.

Pupa and larva unknown.

Diagnosis. Total length of adult male 2.7–2.8 mm. Wing length 2.3–2.4 mm. AR 0.81. Dorsocentrals 7–10, prealars 3–4, scutellars 7–8. LR 1 0.66, BV 1 3.51, SV 1 2.68. Anal point narrow, sharply pointed. Transverse sternopodeme consisting of a narrow arch expanded in the middle. Aedeagal lobe wedge-shaped. Gonocoxite with basal plate in the form of two rounded or rounded triangular tubercles, lower of which is covered with microtrichia and numerous long setae, upper without microtrichia and only with 3–4 setae. Gonostylus narrow, with long crista dorsalis; apex with short macroseta. HR 1.9–2.2.

Remarks. The adult male of Ps. silinka sp. nov. is more closely related to Ps. parva but can be well distinguished from it and from Ps. matafonovi sp. nov. in smaller size (2.7–2.8 mm), AR value (0.81), number of setae on squama (14), narrower gonostylus and by structure of gonocoxite basal plate, which has the form of two rounded or rounded triangular tubercles. In adult males of Ps. parva and Ps. matafonovi sp. nov. are respectively: total lengths 3.1–3.5 mm, 3.6–3.9 mm; AR 0.85–1.0, 1.35–1.87; number of setae on squama 23–30, 30–46. In the same species gonostylus is more massive; gonocoxite has basal plate in the form of two rounded lobelike projections. Gonocoxite of Ps. silinka sp. nov. as in Ps. matafonovi sp. nov., in dorsolateral position at the base of the gonostylus both species are without rounded-triangular protrusion.

Distribution. Known only from the type locality in middle stream of Amur River basin.

Figures

FIGURES 19–25. Adult male of Pseudokiefferiella silinka sp. nov. 19, 21, hypopygium in dorsal view; 20, gonocoxite and gonostylus in dorsal view; 22, basal plate of gonocoxite; 23, transverse sternapodeme and aedeagal lobes; 24–25, gonostylus. Scale bars: 50 μm.