Trichopalpus (Trichopalpus) obscurellus ( Zetterstedt, 1846 )

Ozerov, A. L., 2019, A review of the genus Trichopalpus Rondani, 1856 (Diptera: Scathophagidae) of Russia, Russian Entomological Journal 28 (4), pp. 470-484 : 478-479

Trichopalpus (Trichopalpus) obscurellus ( Zetterstedt, 1846)

Figs 11, 17, 23, 29.

obscurella Zetterstedt, 1846: 2043 ( Cordylura ). Type-locality: “Lapponia Lulensi ad Qvickjock ... alpibus Dalecarlicis ab Eodem” ( Sweden).

subarctica Ringdahl, 1936: 177 ( Microprosopa ). Type-localities: “Ufer von Torneträsk im nördlichen Lappland...bei Åresjön in Jämtland ” ( Sweden).

Recorded in Russian Far East from Chukotka by Ozerov & Krivosheina [2014] .

MATERIAL. Chukotka: Meynypil’gyno env. (62.6283°N 176.9766°E), 25.VII.2015, P.S. Tomkovich (2 ♂♂, ZMUM); Tyumen’ Oblast: the upper reaches of the Pura River (ca. 66.3202°N 77.989°E), 10 km NW of Barasmu Lake, 21–24.VII.1967, Gorodkov (1 ♂, ZISP) .

ADDITIONAL MATERIAL. CANADA: Granet Lk., N.W. T . 68°42’N. 125°37’W. 20.VII.1969, G.E. Shewell (1 ♂, 1 ♀, ZMUM); Coral Harbour , Southampton Is. 17.VII.1948, G.E. Shewell (1 ♂, ZMUM); Chesterfield, N.W. T ., 3.VIII.1950, J. R . Vockeroth (1 ♀, ZMUM) .

DESCRIPTION. Male, female. Medium-sized flies (4.2–5.7 mm long).

Head. Frontal vitta blackish in upper part and reddish yellow in lower half or third, matt. Fronto-orbital plate black, greyish dusted. Face, parafacial and gena reddish yellow. Postgena black, greyish dusted. Postcranium black, greyish dusted, covered with black setae in upper third and pale hairs in lower part. 3 orbitals, 2–4 frontals, 1 ocellar, 1 postocellar (short), 1 inner vertical, 1 outer vertical; 2 pairs of vibrissae present. Antenna black. Postpedicel with more or less rounded upper apical corner, about 2.0 times as long as wide. Arista black, basally thickened, bare. Clypeus and proboscis black. Palpus yellow.

Thorax black, greyish dusted. Acrostical hairs in two rows, dorsocentrals 4+3, including short erect seta on anterior margin of scutum, intra-alars 1+2, supra-alars 1+2, postpronotals 2, notopleurals 2, postalars 2. Proepisternum covered with hairs anteriorly, with 1–2 setae near lower margin. Proepimeron with one seta. Anepisternum covered with hairs in posterior half, with 3–4 setae along posterior margin. Katepisternum greyish dusted completely, covered with hairs in posterior half, with 1 strong seta in upper posterior corner. Anepimeron bare. Scutellum black, greyish dusted, with a pair of basal scutellar and a pair of apical scutellar setae.

Legs black, greyish dusted. Fore femur with a row of posterodorsal setae and a row of long and thin ventral setae. Fore tibia with 1 dorsal and 0–1 posterior/ posteroventral setae, with 1 preapical dorsal/posterodorsal, 1 preapical anterodorsal and 1 apical posterior setae. Mid femur with a row of anterior setae, with 1 preapical posterior and 1 preapical posterodorsal setae. Mid tibia with 1 anterodorsal, 1 posterodorsal and a ring of apical setae. Hind femur with a row of anterodorsal setae and several anteroventral setae in apical half. Hind tibia with 2 anterodorsal, 2 posterodorsal, 1 preapical dorsal, 1 apical/preapical anterodorsal and 1 apical anteroventral setae.

Wing tinged with brownish; veins brown. R 1 bare dorsally. Calypters, margins of calypters, and halteres yellowish or brownish.

Abdomen black, greyish dusted. Male sternite 4 as long as wide (Fig. 11). Male sternite 5 with lobes narrowed apically and curved outward (Fig. 17). Epandrium and surstyli as in Figs 23 , 29 .

DISTRIBUTION. Russia: Chukotka, Tyumen’ Oblast. — Europe (Scandinavia), North America .

Figures

Figs 19–24. Epandrium, cerci and surstyli, lateral view of Trichopalpus spp.: 19 — T. fraternus (Meigen); 20 — T. lacteipennis (Ringdahl); 21 — T. nearcticus (Vockeroth); 22 — T. nigribasis (Curran); 23 — T. obscurellus (Zetterstedt); 24 — T. punctipes (Meigen). Рис. 19–24. Эпандрий, церки и сурстили, вид сбоку видов Trichopalpus: 19 — T. fraternus (Meigen); 20 — T. lacteipennis (Ringdahl); 21 — T. nearcticus (Vockeroth); 22 — T. nigribasis (Curran); 23 — T. obscurellus (Zetterstedt); 24 — T. punctipes (Meigen).

Figs 29–30. Epandrium, cerci and surstyli, dorsal view of Trichopalpus spp.: 29 — T. obscurellus (Zetterstedt); 30 — T. punctipes (Meigen). Рис. 29–30. Эпандрий, церки и сурстили сверху видов Trichopalpus: 29 — T. obscurellus (Zetterstedt); 30 — T. punctipes (Meigen).