Omalus timidus Nurse 1902, comb. nov.

Omalus timidus (Nurse, 1902), comb. nov.

(Figs 4 A–4F)

Ellampus timidus Nurse, 1902: 305. Lectotype ♂ (designated by Kimsey 1986), Pakistan: Peshin (BMNH). Ellampus timidus: Bingham 1903: 420, 1908: 347; Bischoff 1913: 9.

Ellampus hypocrita du Buysson: Nurse 1904: 19 (synonym in error).

Holophris timidus: Kimsey & Bohart 1991: 226.

Material examined. CHINA: 1♀, Guangdong, Nankunshan Provincial Nature Reserve (23°39'28"N 113°55'23"E), 4–6.VI.2011, leg. Z-f Xu (SCAU). 1♀: PAKISTAN: Quetta, Collect. Bingham, Elampus timidus Nurse ♀, timidus Nurse, Bingham typ., paralectotypus ♀, Elampus timidus Nurse (L.D. French), id. nr. 135047 HNHM Hym. coll. (HNHM).

Diagnosis. Chinese specimens of Omalus timidus (Nurse), comb. nov. are similar to O. corrugatus sp. nov. and O. hainanensis sp. nov. by body colouration; but it can be separated from both of them by tarsal claw with four teeth. Moreover, it can be separated from O. corrugatus sp. nov. by impunctate mesoscutum (weakly wrinkled in O. corrugatus).

Redescription. Female (from Guangdong). Body length 4.0 mm (Fig. 4 A). Fore wing length 2.7 mm. OOL = 1.6 MOD; POL = 1.8 MOD; MS = 1.2 MOD; relative length of P:F1:F2:F3 = 1:1:0.6:0.5.

Head. Frons and vertex with small punctures and fine wrinkled interspaces (Fig. 4 B); from ocellar area to occipital area impunctate, with sparse and shallow pits. Scapal basin deep and polished. In lateral view, the longest distance between genal carina and lower margin of eye is 0.9 MOD. Genal carina bisecting MS and closing to lower margin of eye (0.5 MOD). Gena polished with spare dots and wrinkles towards MS. Ocellar triangle isosceles. Postocellar line indistinct.

Mesosoma. Pronotum nearly impunctate, with row of large and deep pits on anterior margin, with shallow and spare punctures on posterior margin, deeper and denser punctures on lateral margins. Mesoscutum impunctate, with shallow, spare and small dots (Fig. 4 C). Notauli pits deep and elongated (about 1.5 MOD). Notauli indistinct. Parapsidal furrows deep and distinct, extending half length of mesoscutum. Lateral field of mesoscutum with row of large punctures along tegula margin. Mesoscutellum with two enlarged anterior foveae (2.5 MOD), separated by 0.8 MOD, with narrow, smooth subtriangular antero-median area; rest of mesoscutellum with large, round and subequal punctures, and longitudinally wrinkled interspaces on posterior margin (Fig. 4 D). Metanotum evenly with larger, deeper and round punctures interspaced subequally, with distinct smooth intervals bearing some shallow dots. Mesopleuron and metapleuron with large, deep and round punctures, and with narrow wrinkled interspaces, without distinct striae. Tarsal claw with four teeth.

Metasoma. T1 impunctate. T2 and T3 almost impunctate, with fine and sparse dots close to lateral margins. T1 without semitransparent rim. T2 with narrow semitransparent rim (0.5 MOD) only apico-medially. T3 with wider semitransparent rim (1 MOD). Apex of T3 without distinct median notch (Fig. 4 F).

Colouration. Antenna black, with scape metallic blue. Head metallic blue to green. The median area of pronotum and mesoscutum black, without metallic reflections; metanotum black, with some metallic reflection; the rest of mesosoma metallic blue. Tegula brown without metallic reflection. Legs metallic bluish-green, with tarsi light brown to testaceous. Metasoma blackish, with greenish-blue metallic reflections on T1 and T2, and T3 laterally; with brown semitransparent rims on T2 and T3.

Male. Unknown.

Distribution. China (Guangdong); Pakistan; India (Bingham 1908).

Remarks. The Chinese specimen shows some dissimilarities comparing with the type: head in frontal view with some striae (without striae in the type); pedicel not metallic blue (metallic blue in the type); POL 1.8 MOD (2.5 MOD in the type); metasoma almost entirely black, with metallic reflections laterally (entirely metallic, dorsally dark blue to violet and laterally blue in the type).

Kimsey & Bohart (1991) included Ellampus timidus into the genus Holophris. We here transfer E. timidus into Omalus because it does not share the main diagnostic characteristics of Holophris, such as double omaulus, double genal carinae and transpleural carina not reaching apex of propodeal angle. In particular, row of large and aligned punctures on mesopleuron may resemble the double omaulus of Holophris. For this characteristics, and other similar morphological characteristics (e. g. the anterior foveae on mesoscutellum and shorten metanotum), O. timidus, O. corrugatus sp. nov. and O. hainanensis sp. nov. are closely related to O. imbecillus and O. pseudoimbecillus, and apparently form a distinct species group.