Ismarus robustus Chen & Yan sp. nov.

Figs 1, 2

Material examined.

Holotype. China • 1♀; Yunnan, Gaoligongshan National Nature Reserve, Dulong River, GLG12; 27°53'51.96"N, 98°20'11.89"E, 1496 m; May-Jun. 2020; Lang Yi leg.; Malaise trap; SCBG 3044338.

Diagnosis.

This species can be easily distinguished from other Ismarus species by the following characters: largely black; mesoscutal suprahumeral sulcus present as six small pits; mesoscutellum with posterior rim excavate and slightly prominent posterolateral corners; hind tibia abruptly incrassate.

Description.

Female. Body length 3.33 mm.

Colour. Body black; antenna entirely black; coxae, trochanters and basal femora of fore and mid legs dark, remainder brown to yellow, with tibia and tarsi becoming paler distally, hind leg mostly black with hind tibia laterally yellow-brown and hind tarsi pale yellow; wings hyaline, veins 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 convex ventrally; A3 as long as A4; A4 1.3 × length of A5; A6-A14 with each segment approximately 1.4 × longer than wide; A15 approximately 2.5 × longer than wide.

Mesosoma. Dorsal pronotal area punctate and setose; lateral pronotal area rugose-punctate ventrally, smooth dorsally; mesoscutum smooth, shiny and convex; mesoscutal suprahumeral sulcus present as six small pits; mesoscutal humeral sulcus deep and finely crenulate, 1.6 × length of tegula; mesoscutellum convex with scattered punctae, posterior rim excavate with slightly prominent posterolateral corners; anterior mesoscutellar pit large and deep, as long as the length of the mesoscutellar disc, distinctly crenulate medially, rugose-punctate posteriorly, median keel strong; mesopleuron smooth, with area below tegula rugulose; metapleuron rugose-punctate and covered with dense, long whitish setae.

Wings. Radial cell completely closed, moderately large, 5.0 × as long as wide and 0.7 × as long as marginal vein.

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

Metasoma. Petiole slightly shorter than wide (8:9), with irregular longitudinal costae dorsally; tergites smooth with scattered fine punctures; base of T2 with several short costae and short median furrow, extending 0.27 × length of T2; sutures between tergites complete and deeply impressed.

Male. Unknown.

Etymology.

Named after the comparatively robust body of this species.

Distribution.

China (Yunnan).