Torulus high on head, above lower margin of eye, hence apex of scape extending above level of vertex; funicle 4-segmented in female, and with 3 branches in male; notauli incomplete; axillae not angulately advanced; scutellum without sublateral grooves; median carina and plicae on propodeum nearly always indistinct or absent in majority of species; petiole distinct though not very long; fore wing and costal cell long and narrow, the fore wing at least 2.6 times as long as wide and costal cell 10–15 times as long as wide.

Holotype ♀ (IMJAU), China: Jilin Province, Jingyuetan National Forest Park of Changchun City (43°79.32'N, 125°45.23'E), 3–9 July 2019, reared by Rui-Jie Wang from Chromatomyia horticola (Goureau) (Diptera: Agromyzidae) on rolled leaves of Ixeris polycephala Cass. and Pterocypsela indica (L.) Shih.

Paratypes : 2♀ and 1♂ (IMJAU), same data as holotype.

The new species is easily distinguished from the other known members of the genus by the following combination of characters: head and mesosoma dark metallic green; back of gaster brown with a large yellowish patch near base, ventral panel of gaster yellow, apex brown; antennae (Fig. 3) with funicle dark brown, scape and pedicel pale yellow, clava uniformly white and 2-segmented; legs yellow with coxae and trochanters white; scutellum longitudinally sculptured, longer than mesoscutum; dorsellum raised-reticulate; propodeum shorter than scutellum, with median carina and plicae complete (Fig. 7).

Female, holotype (Fig. 1). Body length 1.68 mm, fore wing length 1.48 mm. Head and mesosoma dark metallic green. Ocelli and eyes red-brown. Antenna (Fig. 3) with funicle dark brown, scape and pedicel pale yellow. Funicle, scape and pedicel with brown setae; clava, including setae, white. Back of gaster brown with a dumbbell-shaped large yellowish patch near base, ventral panel of gaster yellow, apex brown. Legs yellowish with coxae and trochanters white. Wings hyaline with veins yellowish-brown. Callus with long, white setae.

Figure 1. 

Hemiptarsenus jilinus sp. nov., female, holotype, lateral habitus. Scale bar: 200 µm.

Head in dorsal view 2.5× as wide as long, micro-reticulate, with sparse short and brown setae. POL 1.6× OOL. Head in frontal view nearly quadrate (Fig. 5), 1.1× as wide as high. Eyes bare and oval, 1.4× as long as wide. Malar space 0.4× length of eye, malar sulcus straight and obvious. Lower margin of torulus located distinctly above lower margin of eye. Distance between toruli 0.3× diameter of torulus, 0.2× distance from torulus to eye margin. Antenna (Fig. 3) with scape slender and cylindrical, 8.2× as long as wide, extending far beyond vertex; pedicel 1.8× as long as wide and scape 6.3× as long as pedicel; funicle 4-segmented, F1 2.9× as long as pedicel. Ratio of lengths of F1–4 = 1.1:1.3:1.2:1.0, segments subequal in width. Funicle with numerous longitudinal sensilla. Clava 2-segmented, basal segment 1.6× as long as distal one.

Mesosoma (Figs 6, 9) with coarse and raised reticulation dorsally and laterally, 1.6× as long as wide. Pronotum with 1 pair of black bristles. Mesoscutum (Fig. 6) slightly convex, mid lobe of mesoscutum with 2 pairs of black bristles. Notaulus inconspicuous. Scutellum longitudinally sculptured, longer than mesoscutum, with 2 pairs of stout, black bristles. Axilla micro-reticulate. Dorsellum narrow and reticulate. Propodeum (Fig. 7) shorter than scutellum, with median carina and plicae complete, propodeal spiracle small and round, callus densely setose. Middle area of propodeum between two plicae slightly elevated. Lateral and ventral panel of pronotum and prepectus with coarse reticulate sculpture. Fore wing (Fig. 8) 2.6× as long as wide. Costal cell 13.3× as long as wide, with a row of brown setae. Speculum present, but small. SMV with 6 setae on dorsal surface. Relative lengths of veins SMV:MV:PMV:STV = 15:19:9:5. Several admarginal setae present below MV. Speculum closed and basal setal line present. Precoxae with several long, white setae. Apices of pre- and mesofemora with a black spur. Femora, tibiae and tarsi of all legs with a few rows of short brown setae. Apices of tibiae of all legs with a tibial spur. Metacoxae with several short, black setae.

Metasoma (Fig. 10). Elongate-ovate in dorsal view, 1.8× as long as wide and about as long as head plus mesosoma, apex of gaster acute. Petiole short, transverse, barely visible in dorsal view. Tergites smooth, with sparse short, pale setae. Ratio of lengths of tergites = 7.0:2.5:3.0:3.5:4.0:2.0. Cercal plate with two dark setae of subequal length. Third valvula slightly exerted at apex of gaster.

Male (Fig. 2). Sexual dimorphism evident and smaller than female. Body length 1.61 mm, fore wing length 1.45 mm. Antennae (Fig. 4) with flagellum dark brown, funicle with 3 long branches, with long setae. F1 1.3× as long as pedicel. Ratio of lengths of F1–4 = 1.0:1.6:2.2:3.6. Last tarsomeres brown. Back of metasoma with a semicircular yellowish patch near base. Apex of metasoma obtuse. Genitalia protruding in dorsal view.

Figure 2. 

Hemiptarsenus jilinus sp. nov., male, paratype, lateral habitus. Scale bar: 200 µm.

Apart from the different body sizes of specimens, the main variation is in the color. Back of scape and pedicel pale brown to yellowish; scutellum green with green metallic tinge to blue-green with purple metallic tinge; back of hind femora pale brown to yellowish.

The new species was reared from Chromatomyia horticola on rolled leaves of Ixeris polycephala and Pterocypsela indica Shih in Jingyuetan National Forest Park, Changchun City, where the vegetation is coniferous and broad-leaved mixed forest. The sampling site is slightly disturbed by occasional tourism.

China (Jilin).

The specific name is derived from the type locality’s province name, Jilin Province.

The new species is similar to H. aditus Narendran, 2011 in the general appearance, but differs from the latter in having: 1) Pedicel of antennae pale yellow (black in H. aditus); 2) Clava 2-segmented (1-segmented in H. aditus); 3) Dorsellum raised-reticulate (mostly smooth and shiny in H. aditus). 4) Propodeum with complete median carina (median carina absent in H. aditus) (Narendran 2011).

Figures 3–10. 

Hemiptarsenus jilinus sp. nov., female (3, 5–10) male (4) 3 antenna 4 antenna 5 head, anterior view 6 mesosoma, lateral view 7 propodeum, dorsal view 8 wings 9 mesosoma, dorsal view 10 metasoma, dorsal view. Scale bars: 200 µm (3–10).