Ambositra villumi ( Brazidec & Vilhelmsen, 2022 ), 2024

Chemyreva, Vasilisa G., Vasilenko, Dmitry V. & Perkovsky, Evgeny E., 2024, ‘ Where there are many cattle’ in the Eocene of Ukraine: Review of Ambositra Masner (Hymenoptera, Diapriidae, Ambositrinae) from Rovno amber, with the description of three new species, Zootaxa 5446 (4), pp. 499-516 : 510-514

Ambositra villumi ( Brazidec & Vilhelmsen, 2022) comb. nov.

( Figs 9 , 10 )

Basalys villumi: Brazidec & Vilhelmsen, 2022, p. 76 , figs 1F, 5F–H, 6A.

Material examined. Holotype (NHMD-608360), Baltic amber. Paratype (NHMD-608369) Baltic amber ( Fig. 9 ).

Non-type material (all from Rovno Oblast, Rovno amber, late Eocene, Priabonian ). ♀: SIZK UA-28235 (amber fragment with this female is a triangular prism, sized 9.5: 7.0: 5.0: 2.0 mm) ; ♂, SIZK UA-28112 ; ♂, SIZK UA-28665 ; ♂, SIZK UA-31019 ; ♂, SIZK UA-646 . Klesov : ♂, SIZK K-366; ♂, SIZK K-2402; ♂ and ♀, SIZK K-10214; ♀, SIZK K-26620; ♂, SIZK K-7628; ♂, SIZK K-8445; ♂, SIZK K-6949; ♂, SIZK K-7630; ♂, SIZK K-18501; ♂, SIZK K-8641; ♂, SIZK K-15714; ♂, SIZK K-7631; ♂, SIZK K-7186. Zhovkini , ♂, SIZK ZH-154 . Floodplain of the Veselukha River : ♂, SIZK LKV-492 ; ♂, SIZK LKV-486 ; ♂, SIZK LKV-128 . Perebrody , ♂, SIZK Pe-272. Osova, Grani, Volnoje , ♂, SIZK DO-224 .

Diagnosis. Ambositra villumi differs from all other known Ambositra species by the combination of the following features: head about as long as wide for males and slightly longer than wide (25: 23) for females; slightly higher than width (25: 23) for both sexes; eye 1.8 times as high as malar distance for males (0.9 times for females); gena behind eye about 0.6 times as long as wide of eye in dorsal view (0.9 times for females); occipital carina bare dorsally, covered with foamy structures and setae laterally; scutellum with posterior scutellar pits; epicnemial pit absent ( Figs 10C , 11D ); metapleuron mainly pubescent: entirely pubescent in female ( Fig. 10C ) and with a small bare area medially in males ( Fig. 11D ); submarginal vein straight, its distal end strongly broadened, distance from submarginal vein to anterior margin of the fore wing 0.5 times as wide as distal width of the vein or shorter ( Figs 10E , 11C ); female wing with long marginal fringe ( Fig. 10E ); male A1 shorter than head ( Fig. 11D ), A3 1.35‒1.45 times as long as A4, A4 with carina and emargination developed in basal half of the segment ( Fig. 11F ).

Remarks. Some characters of the holotype and paratypes of Ambositra villumi (Brazidec & Vilhelmsen) such as the wing venation, sculpture of the occipital carinae and the posterior margin of the scutellum ( Fig. 9 ), have been misinterpreted in the description due to light aberrations and some other distortions that occur in amber ( Brazidec & Vilhelmsen, 2022). There is no doubt that the species belongs to the genus Ambositra , but the small differences in the morphology of the A. villumi specimens are the reason for the assumption that A. villumi could be a complex of very close species.

Description. Female. Body length 1.8 mm; fore wing length 1.5 mm; antennae length about 1.1 mm.

Head. Head 1.2 times as long as wide, smooth, with few sparse setae on it in dorsal view. Ocelli moderately large: POL: OD about 1.6, POL: OOL 0.8. Antennal shelf strongly prominent, antennal sockets broadened medial in frontal and lateral view, widely separated ventrally and smooth in frontal view. Face covered with scattered suberect setae. Postantennal excavation large and setose inside. Ventral margin of frons without median process, with weakly prominent lateral processes, not touching walls of antennal sockets. Eyes oval, bare, 0.4 times as high as height of head.

Antennae. Antenna homogeneously pubescent, with non-abrupt clava. Scape as long as A2‒A6 measured together; A2 shorter than A3 and A4 measured together; A3 twice as long as wide, A4‒A7 subquadrate, as long as wide; A8‒A14 elongate; A15 2.9 times as long as wide.

Mesosoma. Pronotal collar very short, vertical; lateral pronotum smooth and mainly glabrous; collar and lateral pronotum anteriorly covered with dense woolly pubescence. Mesoscutum slightly convex and smooth. Scutellum with axillar process short, straight; scutellar disk weakly convex, its lateral margin carinate, posterior mesoscutellar sulcus distinct. Mesopleuron smooth and glabrous laterally, pubescent ventrally; subalar furrow narrow and bare. Metanotum and propodeum in dorsal view not visible. Fore wing 2.9 times as long as its maximum width with venation reaching only 0.26 of the wing length; submarginal vein as described in diagnosis.

Metasoma. Petiole pubescent; its size and sculpture unclear. Metasoma behind petiole 1.5 times as long as mesosoma, slightly depressed and only (T5, T6 and S6) slightly compressed apically. Base of T2 not visible, posteriorly smooth and bare; T3 short, T4 twice as long as T3; T5 and T6 slightly longer than T3. S2 small and densely covered with long setae; S3 mainly bare and smooth; S4 and S5 short, S6 long and tapered. Sternites, T3‒T5 all with few, long scattered long suberect setae.

Figures

FIGURE 9. Ambositra villumi, male, paratype. A—whole body in vento-lateral view; B—metasoma in ventral view; C—fore wing; D—scutellum. Scale bar 0.5 mm.

FIGURE 10. Ambositra villumi, female. A—head and mesosoma in dorsal view; B—whole body in ventro-lateral view; C— head and mesosoma in ventro-lateral view; D—head in frontal view; E—fore wing. Scale bar 0.5 mm.

FIGURE 11. Details of morphology of the Ambositra villumi (A–E) and A. famosa (G), males: A—face (LKV-486); B—head, mesosoma and petiole in dorsal view (K-8641); C—fore wing venation (K-366); D—head and mesosoma in lateral view (UA- 646); E—apex of metasoma in lateral view (K-366); F—antennae, in dorsal view (UA-31019); G—apex of metasoma in dorsal view. Red arrows—cerci. Scale bar: B, D—0.5 mm; F—0.3 mm.