A new species of Hemiptarsenus Westwood (Hymenoptera, Eulophidae) from China, with a key to Chinese species

Abstract A new species, Hemiptarsenus jilinus Tao, sp. nov., is described and illustrated. All the type specimens were reared from Chromatomyia horticola (Goureau) (Diptera: Agromyzidae), a leafminer attacking the plants Ixeris polycephala Cass. and Pterocypsela indica (L.) Shih, in Jilin Province, north-eastern China. A key to Chinese species of the genus is provided.

Leaf miners are serious pests of crops and ornamental plants worldwide (Spencer 1973). Parasitoids play an important role in inhibiting the occurrence of leaf miners (Gratton and Welter 2001). Hemiptarsenus includes numerous species which are poten-tially important for biological control of leaf miners belonging to Diptera, Lepidoptera, Coleoptera and Hymenoptera (Gibson 1997;Burgio et al. 2007;Yang et al. 2015).
In the present paper, a new species, which was reared from Chromatomyia horticola (Goureau) (Diptera: Agromyzidae), is described and a key to the known Chinese species of Hemiptarsenus is given.

Materials and methods
All the specimens were reared from Chromatomyia horticola on rolled leaves of Ixeris polycephala Cass. (Campanulales: Compositae) and Pterocypsela indica (L.) Shih (Asterales: Asteraceae) from Jingyuetan National Forest Park of Changchun City, Jilin Province of China. Different host plants were placed in different insect cages, and each cage was labeled with the collecting date, locality, and host plant. The plants were maintained at 24-26 °C until emergence.
Photographs of the wings were taken with an OLYMPUS SZX16 stereomicroscope. Other photographs were taken with a KEYENCE VHX-2000 digital microscope. The type material of the new species was deposited in the Insect Museum of Jilin Agricultural University (IMJAU), Changchun, China.

Hemiptarsenus Westwood, 1833
Hemiptarsenus Westwood, 1833: 122-123. Type-species: Hemiptarsenus fulvicollis Westwood Diagnosis. 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.
Key to species of Hemiptarsenus Westwood from China (females) Diagnosis. 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).
Description. 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.
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. Variation. 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.
Biology. 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.
Distribution. China (Jilin). Etymology. The specific name is derived from the type locality's province name, Jilin Province.