Ismarus unisulcus Chen & Yan, 2023

Yan, Cheng-Jin, Peng, Yan-Qiong & Chen, Hua-Yan, 2023, Two new species of Ismarus Haliday (Hymenoptera, Ismaridae) from Yunnan, China, ZooKeys 1174, pp. 207-217 : 207

Ismarus unisulcus Chen & Yan sp. nov.

Figs 3 , 4

Material examined.

Holotype. China • 1♀; Yunnan Province, Gaoligongshan National Nature Reserve, Dulong River , GLG13; 27°50'55.81"N, 98°28'3.15"E, 2824 m; 2-15 Jul. 2020; Lang Yi leg.; Malaise trap; SCBG 3044337 . Paratype. China • 1♀; same locality as holotype, but 2-16 Jul. 2020; Lang Yi leg.; Malaise trap; SCBG 3049369 .

Diagnosis.

This species is most similar to I. halidayi Förster but can be distinguished by the following characters: A4 slightly longer than A3 (A4 shorter than A3 in I. halidayi ); median furrow of T2 very short, distinctly less than half the length of T2 (median furrow of T2 long, reaching half the length of T2 in I. halidayi ); radial cell of fore wing 0.75 × as long as marginal vein (radial cell as long as marginal vein in I. halidayi ).

Description.

Female. Body length 2.50-2.64 mm.

Colour. Body black; A1-A9 brown to dark brown, remainder of antenna dark brown; fore and mid legs yellow-brown, with tarsi becoming darker distally, hind leg mostly dark brown with basal coxae somewhat dark and hind femur, trochanter and basal tibia yellow-brown; tegulae yellow-brown; wings hyaline, veins light brown to black-brown.

Head. Head 2.0 × as wide as long in dorsal view; vertex abruptly sloping behind ocelli in lateral view; POL as long as OOL; most of frons with scattered setae, except densely setose ventro-laterally; transverse facial carina slightly convex ventrally; A4 slightly longer than A3; A4 1.5 × length of A5; A6-A14 with each segment less than 1.5 × as long as wide; A15 approximately 2.0 × longer than wide.

Mesosoma. Dorsal pronotal area rugose-punctate and setose; lateral pronotal area rugose-punctate ventrally, smooth dorsally; mesoscutum smooth, shiny and convex, posterior margin with scattered long setae; mesoscutal suprahumeral sulcus present as a single anterior pit; mesoscutal humeral sulcus as long as tegula, deep and crenulate; mesoscutellum smooth and slightly convex, posterior rim rounded; anterior mesoscutellar pit large and deep, shorter than length of the mesoscutellar disc, sparsely punctate posteriorly, median keel weakly defined; mesopleuron smooth, with area below tegula rugulose; metapleuron rugose-punctate and covered with dense, long whitish setae.

Wings. Radial cell closed, moderately large, 5.6 × as long as wide and 0.94 × as long as marginal vein.

Legs. Fore and mid legs slender; hind tibia gradually swollen, its maximum width slightly wider than hind femur.

Metasoma. Petiole slightly shorter than wide (8:9), with strong costae dorsally; tergites smooth with scattered fine punctures; base of T2 with two short costae and a short median furrow, extending 0.37 × length of T2; sutures between tergites complete and deeply impressed.

Male. Unknown.

Etymology.

The name refers to the single furrow present on the base of T2.

Distribution.

China (Yunnan).

Figures

Figure 3. Ismarus unisulcus Chen & Yan, sp. nov., holotype, female (SCBG 3044337) A lateral habitus B head, anterior view C head and mesosoma, dorsal view D head and mesosoma, lateral view E apex of propodeum and basal metasoma, dorsal view F apical metasoma, dorsal view.

Figure 4. Ismarus unisulcus Chen & Yan, sp. nov., holotype, female (SCBG 3044337) A fore wing B antenna C hind tibia.