Holotype: ♀, Mongolia: Bayankhongor, Edringiyn-Nuru Ridge, 100 km SSW of Bayan-Under, 5.IX.1970, leg. V. Zaitzev (ZIN).

Spinolia spinosa sp. nov. is closely related to Central Asian species of the unicolor group, which includes S. chalcites (Mocsáry, 1890), S. rusalka (Semenov, 1901), S. hedychroides (Bingham, 1903) and other small species so far considered synonyms of S. chalcites (Kimsey and Bohart 1991). S. spinosa sp. nov. female can be easily separated from all these species by: lateral pronotal area and propleuron ventrally V-shaped carinate, displaying two teeth in lateral view (Fig. 5D) (vs. unmodified in other species); mesopleuron with large and deep scrobal sulcus subtended by large projecting subrectangular carina (Fig. 5D) (vs. U-shaped carina); sparse, deep and large punctures on mesosoma (Fig. 6D), and sparse and deep punctures on metasoma (vs. punctation with dense, shallow and tiny punctures on mesosoma, denser and shallower on metasoma); antennae yellowish, distinctly elongate (Fig. 5A) (vs. black to dark brown, with short to very short flagellomeres); head, in frontal view, transversely subrectangular (Fig. 6A) and not triangular (Fig. 6B); with bulging eyes, similarly to S. unicolor. It is additionally separated from S. unicolor by punctation, elongate and yellowish antennae and bronze body colour (entirely blue body in S. unicolor, with shortened, blackish flagellomeres).

Female. Body length 6.0 mm. Fore wing length 3.8 mm. OOL = 2.3 MOD; POL = 1.9 MOD; MS = 0.7 MOD; relative length of P:F1:F2:F3 = 1.0:1.4:1.0:0.8; subantennal space: 1.4 MOD. Head. Vertex with deep and contiguous punctures, as large as 0.25 MOD; vertex moderately depressed and impunctate in front of anterior ocellus and impunctate laterad of posterior ocelli; median anterior depression developed to upper scapal basin; TFC faint; frons continuous, without two flattened or concave, striate areas; scapal basin almost flat, laterally densely micro-punctate, medially with contiguous punctures forming transverse winkles (Fig. 6A); lower part of scapal basin medially impunctate and sulcate; apex of clypeus discoloured, W-shaped and bent under, medially the folded part measures 0.6 MOD. Malar space very short, distinctly less than 1 MOD. Antennae elongate, with flagellomeres as long as 1.5 × their width. Mouth parts elongate (as long as 0.8 × head length) and evidently protruding from oral fossa. Mesosoma. Pronotal groove barely visible; anterolateral corner of the pronotum projected to form an acute humeral angle (Fig. 5A); lateral pronotal area ventrally V-shaped carinate forming an acute tooth (Fig. 5D); propleuron ventrally carinate in a large V-shaped tooth (Fig. 5D). Mesosoma punctation dorsally with large, spaced punctures; interspaces medially polished, laterally micro-punctate; notauli incomplete, visible and deep only basally towards the transscutal fissure; parapsidal furrows fully visible; mesopleuron with a large subrectangular area subtended the mesepimeron + mesepisternum; posterior propodeal projections narrow, acute and downward directed. Wing venation unmodified, with long Rs bending slightly away from costal margin, leaving marginal cell broadly open. Metasoma. Punctation on T1 with tiny, sparse punctures (separated by 1–4 PD) (Fig. 6D), laterally micro-punctate on interspaces; T2 with larger and deeper punctures, anterodorsally denser (0.1–2 PD), laterally micro-punctate on interspaces; T3 with coarse to contiguous small punctures; T3 pit row barely sunken, with small, round pits, equally spaced; posterior pit row area almost polished, with a few, sparse, tiny punctures; T3 with two lateral angles and fully bordered by hyaline margin. Metasomal invaginated T5, T6, and S5 with several dorsal and lateral lobes. S2 black spots oval, transversally placed and separated 0.5 MOD each other. Colouration. Body coppery-bronze, darker to black on median area of mesoscutum; ventrally golden to copper; tegulae golden to non-metallic yellowish on outer margin; tarsi dark brown. Mandible brown, lighter medially. Scape and pedicel coppery, antennomeres yellowish-orange, darker on distal segments. Legs pale coloured, with slight metallic reflections, with non-metallic proximal and distal joints; tarsi yellowish. Forewings hyaline, slightly amber, with light brown veins. Vestiture. Whitish, short and sparse setae on head and mesosoma (up to 1.5 MOD long); face with short whitish setae (less than 1.0 MOD); metasoma with short (less than 1. MOD) whitish, sparse setae on T3 and ventrally on S2 and S3 and femora.

Male. Unknown.

The specific epithet spinosa (feminine) is derived from the Latin adjective spinosus (thorny) for the long and acute teeth ventrally displayed on pronotum and propleuron and clearly visible in lateral view (Fig. 5D).

Mongolia (Bayankhongor).