Omalus stella

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 : 72

Omalus stella (Semenov & Nikol'skaya, 1954)

( Figs 3 A–3F)

Ellampus stella Semenov & Nikol'skaya, 1954: 93. Lectotype ♀ (designation by Kimsey 1986), Tajikistan: Stalinabad [Dushanbe] (ZIN).

Omalus stella: Kimsey & Bohart 1991: 249 .

Material examined. CHINA: 1♀, [oasis Sa-zhou] = Xinjiang, Chanji, [Gashunskaya Gobi], 28.VII.1895, leg. P.K. Kozlov ( ZIN).

Diagnosis. Omalus stella (Semenov & Nikol'skaya) is similar to O. timidus ( Nurse, 1902) for tarsal claw with four teeth. However it can be separated from the latter by the following characteristics: pronotum flat laterally (deeply impressed in O. timidus ); notauli distinct and complete (indistinct in O. timidus ); semitransparent rim narrow (<1MOD) and apical margin widely interrupted (semitransparent rim> 1 MOD and continuous in O. timidus ).

Redescription. Female. Body length 3.5–4.2 mm ( Fig. 3 A). Fore wing length 2.5–3.0 mm. OOL = 1.8 MOD; POL = 2.0 MOD; MS = 0.9 MOD.

Head. Frons and vertex with large punctures ( Fig. 3 B); from ocellar area to occipital area smooth, 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 1.2 MOD. Genal carina bisecting MS. Gena with spare dots and wrinkles. 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. 3 C). Notauli pits deep and elongated (about 2 MOD). Notauli distinct and complete. Parapsidal furrows deep and distinct, extending over half length of mesoscutum. Lateral field of mesoscutum with row of large punctures along tegula margin. Mesoscutellum with two narrow and enlarged anterior foveae (1.5 MOD), separated by 1 MOD, with smooth subtriangular antero-median area; rest of mesoscutellum with large, round and subequal punctures ( Fig. 3 C). Metanotum evenly with larger, deeper and round punctures interspaced subequally, with distinct smooth intervals. Mesopleuron and metapleuron with large, deep and round punctures, without wrinkled interspaces or striae ( Fig. 3 D). Tarsal claw with four teeth.

Metasoma. T1 almost impunctate, with fine and sparse dots close to lateral margins. T2 and T3 with fine and sparse dots, and denser on lateral margins. T1 without semitransparent rim. T2 with narrow semitransparent rim (0.5 MOD). T3 with narrow semitransparent rim (0.5 MOD), largely interrupted apico-medially ( Fig. 3 F).

Colouration. Antenna black, with scape and pedicel metallic green. Body metallic green with golden reflections. Tegula metallic green. Legs metallic green, with tarsi light brown to testaceous.

Male. Not available in this study, males from other localities do not differ from female.

Distribution. China (Xinjiang); Tajikistan (Semenov & Nikol'skaya 1954).

Figures

FIGURE 3. Omalus stella (Semenov & Nikol'skaya), ♀, lectotype, Tajikistan. A. Habitus, lateral view; B. Head, frontal view; C. Head and mesosoma, dorsal view; D. Head and mesosoma, lateral view; E. Metasoma, dorsal view; F. T 3, posterior view.