Coenosia luxia, Sorokina, 2023

Sorokina, Vera S., 2023, A key to the Russian species of the genus Coenosia Meigen (Diptera, Muscidae), with the description of one new species and new synonymies, Zootaxa 5389 (1), pp. 79-107 : 80-82

Coenosia luxia sp. nov.

Figs 1 A–F

Type material examined: Holotype ♂, Russia, Magadan region, environs of Evensk village , coastal meadow, sweep in grass, 61°54'N 159°12'E, 1 m, 23.vii.2020, leg. N. Tridrikh ( SZMN) . Paratypes 4 ♂♂, Russia, Magadan region, environs of Evensk village , coastal meadow, sweep in grass, 61°54'N 159°12'E, 1 m, 10.vii.2020, leg. N. Tridrikh (1♂ in ZISP, 3♂♂ in SZMN) . 1 ♂ 3♀♀, Russia, Magadan region, environs of Evensk village , coastal meadow, sweep in grass, 61°54'N 159°12'E, 1 m, 18.vii.2020, leg. N. Tridrikh ( SZMN) . 1 ♀, Russia, Magadan region, environs of Evensk village , coastal meadow, sweep in grass, 61°54'N 159°12'E, 1 m, 21.vii.2020, leg. N. Tridrikh ( ZISP) . 1 ♀, Russia, Magadan region, environs of Evensk village , coastal meadow, sweep in grass, 61°54'N 159°12'E, 1 m, 26.vii.2020, leg. N. Tridrikh ( SZMN) . 1 ♂, Russia, Magadan region, environs of Evensk village , coastal meadow, sweep in grass, 61°54'N 159°12'E, 1 m, 27.vii.2020, leg. N. Tridrikh ( SZMN) . 1 ♀, Russia, Magadan region, environs of Evensk village , coastal meadow, white pan trap, 61°54'N 159°12'E, 1 m, 27– 30.vii.2020, leg. N. Tridrikh ( SZMN) . 1 ♂, Magadan region, 10 km E Evensk village, S. Garmanda river , 61º52’N 159°23'E, 10 m, 24.vii.2020, leg. N. Tridrikh ( SZMN) .

Etymology. The specific name “luxia ” is from the Latin “lux” for the Russian “svet” (light), and the species is dedicated to my sister Sveta Sorokina for her help with my field work on flies over many years.

Diagnosis: Very small whitish-grey species with dark legs, with long lower calypter and with a spine-like dorsal tip of postpedicel. The species is very similar to Coenosia grisella Hennig, 1961 , described from Tajikistan, from which it can be separated by the wide gena, two proepisternal setae, colour of scutum and abdomen and the shape of surstylus of male terminalia.

Description: Male: body 2.3–2.5 mm; wings 2.2–2.3 mm.

Head: Ground-colour black with dense silvery pruinosity. Lower facial margin not projecting beyond level of antennal base. Frontal vitta 2 times as wide as a fronto-orbital plate. Ocellar triangle reaching middle of frontal vitta. Frons with 2 pairs of frontal setae (sometimes a short hair between them). Width of parafacial at middle equal to 1/2 of width of postpedicel. Height of gena 1.5–2.0 times width of postpedicel. Antenna black, postpedicel long, reaching to level of oral margin, ca. 3.0 times as long as wide, with a spine-like dorsal tip ( Fig. 1A ). Arista black, very short- pubescent, appearing bare. Palpus black. Proboscis long, shining.

Thorax: Black, densely withish-grey dusted. Prosternum bare. Ground-setulae of postpronotal lobe setulose, not spinulose. Scutum with 3 brown longitudinal vittae and light brownish dust between postsutural dc ( Fig. 1B ). Scutellum grey dusted, with brownish dust on dorsal surface. Presutural acr in 2 even rows; 1 + 3 dc. Two proepisternal setae. Apical and basal scutellars well developed and equal.

Wings: Light coloured, with a slight brownish tinge on apical half. Costa with weak spinules. Calypters white; lower one much longer than upper one. Haltere light yellow.

Legs: All black with whitish-grey dust with the exception of brownish trochanters and knees. Pulvilli not elongate. Fore tibia with 1 submedian p. Mid femur with 1–2 setae on ventral surface in basal third, without preapical a, without any pv, and 1 preapical p seta. Mid tibia with 1 ad, and with 1 pd which is a little shorter than ad. Hind femur with 1 av in apical third and with 1 pv in basal half near to middle. Hind tibia with 1 av and 1 ad, without pd; preapical ad and pd much shorter preapical d seta; preapical setae not close together.

Abdomen: Black with thick whitish-grey dust, conical, no longer than thorax. Tergites 1+2–5 with pairs of indistinct brown spots and brownish dust between them. Sternite 5 with a shallow notch, with tips rounded and pointed ( Fig. 1F ).

Terminalia : Surstylus longer than broad, slightly curved at the distal tip towards cercus ( Fig. 1D ). Cercus longer than broad, trapezoidal, sclerotised, setulose (hair-like setae), with apical margin broadly rounded ( Fig. 1E ). Hypandrium longer than wide, rectangular ( Fig. 1D ). Aedeagus with phallapodeme straight, strongly sclerotised, not longer than hypandrium in lateral view; pregonites oval-elongated towards epandrium, ventrally fused with the hypandrium; hemispherical postgonites about the same size as pregonites; epiphallus developed, mostly sclerotised; distiphallus tubular, and sclerotised in basal half ( Fig. 1D ).

Female: body 2.5–2.7 mm; wing 2.1–2.2 mm.

Similar to male, but differing from it as follows: body darker, greyish pruinose ( Fig. 1C ). Frontal vitta 3 times as wide as a fronto-orbital plate. Height of gena 1.5–1.8 times width of postpedicel. Postpedicel ca. 2.5–3.0 times as long as wide. Scutum with light brown dust, with indistinct brown longitudinal vittae. Scutellum brown dusted. Legs completely black with grey dust. Mid femur with 2–3 setae on ventral surface of basal third. Hind femur with a row of short av setae and 1 strong long av in apical third, with 2 pv in basal half.Abdomen brownish dusted dorsally, with indistinct small brown spots on tergites 3–4 and with a longitudinal brown vitta on tergite 5.

Distribution. Palaearctic: Russia (Magadan region).

Figures

FIGURE 1. Coenosia luxia sp. nov. A. Holotype, male, lateral view. B. Holotype, dorsal view. C. Paratype, female, lateral view. D. Terminalia, lateral view. E. Cercal plate, dorsal view. F. Sternite 5. Bare: 1 mm.