Trichopalpus (Chaetosa) nigribasis ( Curran, 1927 )

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

Trichopalpus (Chaetosa) nigribasis ( Curran, 1927) Figs 10, 16, 22, 28.

nigribasis Curran, 1927: 255 ( Tricopalpus ). Type-locality: “Banff”, Alberta ( Canada).

pilirostris Ringdahl, 1936: 178 ( Chaetosa ). Type-locality: “bei Tromsö im nördlichen Norwegen ” ( Norway).

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

MATERIAL. Amur Oblast: town Zeya (53.7485°N 127.2614°E), 11 and 18. VI .1978, A. Shatalkin (2 ♀♀, ZMUM); Arkhangelsk Oblast: Solvychegovsk (61.3421°N 46.9132°E), 15.VIII.2010, D. Gavryushin (1 ♀, ZMUM) .

DESCRIPTION. Male, female. Medium-sized flies (5.0– 5.8 mm long).

Head. Frontal vitta black, only along lunula yellow, matt. Fronto-orbital plate black, greyish dusted. Face, parafacial and gena yellow. Postgena black, greyish dusted. Postcranium black, greyish dusted, covered with black setae in upper third and pale hairs in lower part. 3 orbitals, 3–5 frontals, 1 ocellar, 1 postocellar (very small), 1 inner vertical, 1 outer vertical; 2 pairs of vibrissae present. Antenna black. Postpedicel with acute upper apical corner, about 2.5 times as long as wide. Arista black, basally thickened, bare. Clypeus and proboscis black. Palpus yellow in apical part and black basally, sometimes blackish completely.

Thorax black, greyish dusted. Acrostical hairs in two rows, dorsocentrals (3–4)+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. Coxae and trochanters of all legs black. Femora and tibiae of all legs yellow. Tarsi of all legs from dark yellow to blackish. Fore femur with rows of posterodorsal (normal) and ventral (long and thin) setae. Fore tibia with 1 dorsal and 1 posterior/posteroventral setae in lower half, with 1 preapical dorsal/posterodorsal, 1 preapical anterodorsal and 1 apical posterior setae. Mid femur with a row of anterior setae, with 1 preapical anterior/anterodorsal and 1 preapical posterodorsal setae. Mid tibia with 1 anterodorsal, 1 posterodorsal and 1 ventral setae near middle, also with a ring of apicals. Hind femur with a row of anterodorsal setae and several anteroventral setae in apical half. Hind tibia with 2 anterodorsal, 2 posterodorsal, 1 anteroventral, 1 preapical dorsal, 1 apical/preapical anterodorsal and 1 apical anteroventral setae.

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

Abdomen black, greyish dusted; female syntergite 1+2 and tergites 3–6 with a row of marginal setae. Male sternite 4 square (Fig. 10). Male sternite 5 with broad rounded lobes, each carrying small tubercle at the middle of internal side and at apex (Fig. 16). Epandrium and surstyli as in Figs 22 , 28 .

DISTRIBUTION. Russia: Amur Oblast, Arkhangelsk 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 25–28. Epandrium, cerci and surstyli, dorsal view of Trichopalpus spp.: 25 — T. fraternus (Meigen); 26 — T. lacteipennis (Ringdahl); 27 — T. nearcticus (Vockeroth); 28 — T. nigribasis (Curran). Рис. 25–28. Эпандрий, церки и сурстили, сверху видов Trichopalpus: 25 — T. fraternus (Meigen); 26 — T. lacteipennis (Ringdahl); 27 — T. nearcticus (Vockeroth); 28 — T. nigribasis (Curran).