Spilomicrus succinalis Brazidec & Vilhelmsen 2022, sp. nov.
Creators: name: Brazidec, Manuel
name: Vilhelmsen, Lars
Publisher: name: Zenodo
Year: 2022
Subjects: Biodiversity
Taxonomy
Animalia
Arthropoda
Insecta
Hymenoptera
Diapriidae
Spilomicrus
Spilomicrus succinalis

description: Spilomicrus succinalis sp. nov.
urn:lsid:zoobank.org:act: C6DACEAE-5CBB-4BC5-A414-FC2458978B3D
Figs 1H, 6E–H, Table 1
Diagnosis
Head higher than long, minutely punctuate on vertex; scape with distinct punctuations; pedicel pearshaped, narrower at base; F1–F5 as long as wide; F6–F11 forming non-abrupt clava; F11 conical, longer than F10 (Fig. 6E, G–H); occipital flange foveate (Fig. 6F); pronotum laterally with small foveae along posterior margin (Fig. 6E); mesoscutum flat and smooth, with long hairs; notauli convergent, interrupting before posterior margin of mesoscutum; anterior scutellar pit bifoveate; posterior scutellar pits present (Fig. 6F); propodeum carinate; Sc+R pigmented, marginal vein wider than long, r-rs as long as marginal vein (Fig. 1H); first fore tarsomere bearing row of setae along inner margin; first hind tarsomere not longer than following two combined; petiole 1.5 times as long as wide; T2 with anterior margin wrinkled (Fig. 6F); two ring-like segments visible after T2.
Etymology
The species name derives from ‘Succinite’, a name given to Baltic amber due to its chemical composition. The specific epithet is to be treated as an adjective.
Type material
Holotype NHMD-607131, a complete female; paratype NHMD-608344, a complete female; paratype NHMD-608354, a complete female.
Locality and horizon
Baltic amber is considered to be of Bartonian–Priabonian age, ca 34–38 Ma.
Description
Female
BODY. BL = 1.96–2.65 mm. Head higher than long (HeL = 0.29–0.50 mm), with several hairs dorsally; head minutely punctuate on vertex; eye oval, higher than long; antennae inserted on shelf at level with lower half of eye; toruli distinct and slightly protruding; scape with distinct punctuations, 4.2 times as long as wide; pedicel pear-shaped, narrower at base; F1–F5 compact, as long as wide; following flagellomeres widening to form non-abrupt club; F11 wider and longer than F10, conical (antennomeres length of holotype, in mm: Sc-0.25; P-0.09; F1-0.05; F2-0.04; F3-0.04; F4-0.04; F5-0.05; F6-0.06; F7-0.06; F8-0.06; F9-0.08; F10-0.08; F11-0.10); mandibles simple, not forming beak; occipital flange foveate.
MESOSOMA. Shorter than metasoma (MsL = 0.67–0.83 mm); pronotum not elongate, not visible in dorsal view, laterally with small foveae on posterior margin; mesoscutum wide, flat and smooth, with several long hairs; notauli present, deep, convergent posteriorly but not reaching posterior margin of mesoscutum; anterior scutellar pit bifoveate; scutellum with posterior scutellar pits present; propodeum carinate, with prominent median keel. Fore wing extending beyond gaster (FwL = 1.27–1.81 mm), hyaline and covered with micropubescence, rounded, bordered with long setae shortening toward wing apex; Sc+R pigmented and distinctly separated from wing margin; marginal vein thickening at apex of Sc+R and almost two times as wide as long; r-rs pigmented and elongate, almost as long as marginal vein. Hind wing half as long as fore wing; only C pigmented. Legs slender, with numerous long setae; first fore tarsomere bearing row of erect setae on inner margin; fore tibial spur long, curved; tibial spur formula 1-2-2; first hind tarsomere not longer than following two combined.
METASOMA. Petiole longer than wide (PtL = 0.14–0.21 mm; PtW = 0.10–0.13 mm), covered with longitudinal carinae, glabrous; gaster beyond petiole broadly oval and narrowed at apex (GL = 0.87– 1.11 mm; GH = 0.23–0.43 mm), smooth and with few setae; T2 longest, covering two thirds of gaster, with anterior margin slightly wrinkled, overlapping petiole; S2 longest, as long as T2; segments 3 and 4 ring-like; segment 5 longer than 3 and 4 combined and sharply pointed at apex; ovipositor projecting as short stub.
Male
Unknown.
Comments
Using Nixon’s (1980) and Masner & García’s (2002) keys to the genera of Diapriinae, Spilomicrus succinalis sp. nov. clearly keys out to Spilomicrus because of the following characters: antenna with 13 segments, flagellum thickened towards apex, frons unarmed, ocellar triangle in the ocular zone, notauli present, scutellum with an anterior bifoveate pit, wings fully developed, fore wing with pigmented Sc+R, marginal vein not more than one and a half times as long as wide, anterior margin of syntergite straight, without a furrow or a cleft at base.
Following the key to the British species of Nixon (1980) and to Eastern Palaearctic species of Chemyreva (2018), S. succinalis sp. nov. keys out near S. comatus Chemyreva, 2015. It differs from this species by having F11 longer than F10, the petiole less than two times as long as wide and lacking the long hairs on the postgena (Chemyreva 2015).
description: Published as part of Brazidec, Manuel & Vilhelmsen, Lars, 2022, New species of belytine and diapriine wasps (Hymenoptera: Diapriidae) from Eocene Baltic amber, pp. 57-86 in European Journal of Taxonomy 813 on pages 79-81, DOI: 10.5852/ejt.2022.813.1733, http://zenodo.org/record/6468167