Omalus hainanensis Rosa, Wei & Xu

Rosa, Paolo, Wei, Na-Sen & Xu, Zai-Fu, 2015, Contribution to the genus Omalus Panzer, 1801 of China, with descriptions of two new species (Hymenoptera, Chrysididae), Zootaxa 4013 (1), pp. 67-76 : 69-72

Omalus hainanensis Rosa, Wei & Xu , sp. nov.

( Figs 2 A–2F)

Material examined. Holotype: ♀, CHINA: Hainan, Bawangling National Nature Reserve (19°7'31"N 109°14'6"E, 7–11.VII.2006, leg. J-x Liu & L-q Weng ( SCAU). Paratypes: 2♀, CHINA: Hainan, Diaoluoshan National Nature Reserve (18°39'32"N 109°54'56"E), 7–8.V.2008, leg. H-y Chen ( SCAU).

Diagnosis. Omalus hainanensis sp. nov. is similar to O. corrugatus sp. nov. and O. timidus ( Nurse, 1902) for body colouration; however it can be separated from O. corrugatus sp. nov. by impunctate mesoscutum (weakly wrinkled in O. corrugatus sp. nov.); and from O. timidus by tarsal claw with three teeth (four teeth in O. timidus ).

Omalus hainanensis sp. nov. is also similar to O. potanini ( Semenov, 1932) and can be separated by elongated anterior foveae on mesoscutellum (without anterior foveae in O. potanini ) and by the evenly punctate mesoscutellum (widely polished in O. potanini ).

Description. Female. Holotype. Body length 4.1 mm ( Fig. 2 A). Fore wing length 2.4 mm. OOL = 1.7 MOD; POL = 2.2 MOD; MS = 1 MOD; relative length of P:F1:F2:F3 = 1:1:0.5:0.5.

Head. Head with shallow punctures on face and vertex, with interspaces wrinkled among punctures ( Fig. 2 B); punctures aligned and laterally touching. In lateral view, the longest distance between genal carina and lower margin of eye is 1.5 MOD. Genal carina bisecting MS. Scapal basin deep, polished and glabrous. Ocellar triangle isosceles. Postocellar line absent. Gena with fine and oblique wrinkles, without punctures. Occipital area beneath ocellar area smooth and impunctate.

Mesosoma. Pronotum nearly impunctate, with row of large and deep pits on anterior margin, with shallow, spare and small punctures on posterior margin, deeper and denser (0–0.5 PD) punctures on lateral margins. Mesoscutum impunctate ( Fig. 2 C). Notauli pits deep and elongated (1.2 MOD). Notauli indistinct ( Fig. 2 D). Parapsidal furrows indistinct. Lateral field of mesoscutum with row of large punctures along tegula margin. Mesoscutellum with two enlarged anterior foveae (3 MOD), close to each other and separated by 0.5 MOD; with smooth and small subtriangular antero-median area; rest of mesoscutellum with large, round and subequal punctures, and wrinkled interspaces on posterior margin ( Fig. 2 D). Metanotum evenly with larger, deeper and round punctures subequally interspaced, with distinct smooth intervals bearing some shallow dots ( Fig. 2 D); bottom of punctures blackish contrasting with metallic green to blue interspaces. Mesopleuron and metapleuron with large, deep and round punctures, punctures transversally corrugated and aligned with wrinkled intervals; diameter of punctures increasing from alar fovea to omaulus. Tarsal claw with three teeth.

Metasoma. T1 impunctate. T2 almost impunctate, with fine and spare dots close to lateral margins. T3 with more incised dots laterally. T1 without semitransparent rim. T2 and T3 with wide semitransparent rims (1 MOD). Apex of T3 without distinct median notch ( Fig. 2 F).

Colouration. Antenna black, with scape and pedicel metallic bluish. Head entirely metallic blue. Mesoscutum black; rest of mesosoma greenish-blue, with blackish punctures on metanotum ( Fig. 2 D). Tegula brown, without metallic reflection. Leg metallic bluish-green, with tarsi brown. T1 and T2 black, without metallic reflection. T3 mostly metallic green to blue.

Male. Unknown.

Distribution. China (Hainan).

Etymology. The species is named after the type locality.

Figures

FIGURE 2. Omalus hainanensis sp. nov., ♀, holotype, Hainan. A. Habitus, lateral view; B. Head, frontal view; C. Head, pronotum and mesoscutum, dorsal view; D. Mesoscutum, mesoscutellum, and metanotum, dorsal view; E. Metasoma, dorsal view; F. T 3, posterior view. Scale bar: mm.