Omalus helanshanus sp. n. Plates 7, 8

Material examined.

Holotype, ♀ (SCAU), Inner Mongolia, Helanshan, Gulaben, Dayanggou (39°5'24.90"N, 106°3'32.35"E), 27.VII.2010, Hong-fei Chai, No. SCAU-O0011. Paratypes: 3 ♀♀ (SCAU), Inner Mongolia, Helanshan, Gulaben, Dayanggou, 27.VII.2010, Hong-fei Chai, No. SCAU-O0012-0014; 2 ♀♀ (SCAU), Inner Mongolia, Helanshan, Shuimogou (38°57'25.97"N, 105°52'22.90"E), 30.VII.2010, Hong-fei Chai, No. SCAU-O0015, SCAU-O0016; 1 ♀ (SCAU), Inner Mongolia, Helanshan, Shuimogou, 30.VII.2010, Jie Zeng, No. SCAU-O0017; 3 ♀♀ (SCAU), Inner Mongolia, Helanshan, Habeigou, Huangliangzi (38°51'49.22"N, 105°53'17.40"E), 9.VIII.2010, Jie Zeng, No. SCAU-O0018-O0020; 5 ♀♀ (SCAU), Inner Mongolia, Helanshan, Halawuchagou (38°51'40.66"N, 105°52'10.49"E), 10.VIII.2010, Hong-fei Chai, No. SCAU-O0021-O0025; 1 ♀ (SCAU), Inner Mongolia, Helanshan, Halawuchagou, 10.VIII.2010, Cheng-jin Yan, No. SCAU-O0026; 11 ♀♀ (SCAU), Inner Mongolia, Helanshan, Halawubeigou (38°51'33.33"N, 105°53'28.67"E), 9.VIII.2010, Hong-fei Chai, No. SCAU-O0027-0037; 1 ♀ (SHEM), Inner Mongolia, Helanshan, Halawu (38°52'5.39"N, 105°45'29.34"E), 2250 m, 10.VIII.2010, Xu-feng Zhang and Feng-li Cui, No. 34020573; 1 ♀ (SHEM), Inner Mongolia, Helanshan, Halawu, 2800 m, 9.VIII.2010, Xu-feng Zhang and Feng-li Cui, No. 34020592; 1 ♀ (SHEM), Inner Mongolia, Helanshan, Halawu, 2250 m, 10.VIII.2010, Xu-feng Zhang and Feng-li Cui, No. 34020129.

Diagnosis.

Omalus helanshanus sp. n. is similar to Omalus potanini Semenov-Tian-Shanskij based on the indistinct notauli and scutellum without flattened fovea on anterior margin; it also resembles Omalus tibetanus sp. n. based on the elongate metasoma and the similar sculpture. However, Omalus helanshanus sp. n. can be distinguished by the combination of the following characters: postocellar line present, apex of T-III with brownish transparent rim and median notch faint. Comparison with Omalus potanini Semenov-Tian-Shanskij is based on the description of the male, since the female of Omalus potanini is unknown.

Description.

Female (n = 30). Body length 3.9-4.9 mm (Plate 7). Forewing length 3.1-4.4 mm. MS = 0.9 MOD.

Head. Face with large, round, dense (0-0.5 PD), shallow punctures (Plate 8A). Scapal basin deep, smooth, glabrous (Plate 8A). Ocellar triangle isosceles. Postocellar line shallowly impressed (Plate 8B). Gena without wrinkles or with very fine wrinkles.

Mesosoma . Pronotum almost impunctate medially, with small, deep pits on anterior margin; with large, dense (0-0.5 PD) punctures laterally (Plate 8B). Mesoscutum polished, almost impunctate (Plate 8D); notauli indistinct, almost complete, impressed as fine lines, with notaulic pit round and short; parapsidal lines indistinct (Plate 8D). Scutellum without flattened fovea on anterior margin; with broad, impunctate median area extending along its length, slightly convergent posteriorly (Plate 8D); with shallow, areolate punctures laterally, becoming larger and deeper towards alar foveae. Mesopleuron without striae between punctures (Plate 8C). Metanotum evenly round, with large, deep, areolate-reticulate punctation (Plate 8D). Propodeum with lateral margin concave before propodeal angle; propodeal angle small, short, pointing backwards (Plate 8D). Tarsal claw with three teeth.

Metasoma. Elongate (Plate 8E), L/W = 10/7. T-I and T-II almost impunctate dorsally, with fine, scattered punctures towards the margins and laterally (Plate 8E). T-III with fine, denser punctures than those on T-II; apex of T-III with narrow (1/2 MOD), brownish transparent rim, with faint median notch (Plate 8F).

Colouration. Head and mesosoma mostly metallic bluish-purple, with distinct or faint metallic green reflections on mesopleuron, metanotum, metapleuron, and propodeum. Antenna black, with scape and pedicel metallic green. Tegula purple, with apex brownish. Leg metallic bluish-purple, with tarsus brown. Metasoma metallic bluish-purple, with some metallic green reflections.

Male. Unknown.

Distribution.

China (Inner Mongolia).

Biology.

Unknown. Collected from July to August.

Etymology.

The species is named after the type locality.