Ambositra masneri Chemyreva & Vasilenko & Perkovsky 2024, sp. nov.

Ambositra masneri Chemyreva sp. nov.

(Fig. 8)

Holotype: ♂, SIZK L-388, Voronki, Rovno Oblast, Rovno amber, late Eocene, Priabonian. Amber fragment with holotype is a parallelepiped, sized 10.5: 1.5: 1.2 mm.

Diagnosis. Ambositra masneri sp. nov. differs from all other known Ambositra species by the following combination of characters: head slightly wider than long (22: 21) and slightly higher than width (12: 11); eye twice as high as malar distance; gena behind eye about 0.6 times as long as width of eye in dorsal view; occipital carina bare dorsally, covered with foamy structures and setae laterally; scutellum with posterior scutellar pits; epicnemial pit absent; metapleuron and lateral side of propodeum bare medially and setose otherwise; distal end of submarginal vein broadened and situated very close to anterior margin of the wing (Fig. 8C); A1 shorter than head, A3 about 1.9 times as long as A4; A4 with emargination and carina developed in the basal half of the segment.

Description. Male. Body length 1.3 mm; fore wing length 1.2 mm; antennae length about 1.4 mm.

Head. As long as wide, smooth, with few sparse setae on it when viewed dorsally. Ocelli large, POL: OD about 1.4, POL: OOL 0.6. Antennal shelf strongly prominent, antennal sockets broadened medially in frontal and lateral view, widely separated ventrally and smooth in frontal view. Face covered with scattered suberect setae. Postantennal excavation large and densely setose inside. Ventral margin of frons indistinct. Eyes oval, bare, 0.5 times as high as height of head.

Antennae. Antenna filiform, homogeneously pubescent. Scape 1.2 times as long as A3, A3 twice as long as A2 and 5.2 times as long as wide; A4 0.5 times as long as A3, with carina and excavation developed in basal half; A5‒ A13 elongate, about 3.1 times as long as wide; A14 0.8 times as long as A3 but longer than all other flagellomeres.

Mesosoma. Pronotal collar very short, vertical; lateral pronotum smooth and mainly glabrous; collar and lateral pronotum anteriorly covered with dense woolly pubescence. Mesoscutum as long as its maximum width, weakly convex, smooth, with few scattered long suberect setae. Scutellum 1.7 times as wide as long; anterior scutellar pit 0.3 times as wide as scutellum; axilla smooth; axillar process straight, longer than shortest distance between it and anterior scutellar pit; scutellar disk weakly convex, with distinct posterior mesoscutellar sulcus, lateral rim and axillar depression smooth. Mesopleuron smooth and glabrous laterally, pubescent ventrally; subalar furrow narrow and bare. Metanotum sparsely setose; metanotal trough smooth; metascutellum with high median and lateral carinae. Metapleuron with anteroventral metapleural pit pubescent inside. Characters of propodeum unclear. Fore wing 2.6 times as long as its maximum width.

Metasoma. Petiole pubescent and with what may be foamy structures ventrally; cylindrical, ventrally covered with deep grooves. Dorsal side of metasoma invisible, apical tergite with one segmented cerci. S2 small and densely covered with long setae; S3 the largest sternite, densely pubescent anteriorly, smooth and with few scattered suberect setae posteriorly; S4‒S6 short and equal in length; S7 slightly longer than S6; S8 sub-triangular; S4‒S8 all covered with few scattered long suberect setae.

Etymology. The new species is named in honor of the famous entomologist and expert on Diaprioidea, Proctotrupoidea and Platygastroidea, Dr Lubomír Masner, who was the first and only person to conduct research on extant and extinct wasps of the genus.