Aulacus walkeri Jennings & Parslow & Austin 2018, sp. nov.

Aulacus walkeri Jennings & Parslow, sp. nov.

Figs 51, 67.

Material examined. Holotype. ♀, “Mornington Vict[oria] 12.2.17 [1917] (MVMA). Paratypes. Victoria: 3♂, Bendigo, J.E. Dixon, 1920 (MVMA).

Description. FEMALE. Length. 8.0 mm, excluding ovipositor.

Colour. Head and mesosoma black, scape and pedicel orange, ventral pronotum and dorsal metapleuron lighter, all coxae dark orange remainder of legs orange except hind femora and tibia dark orange, metasoma orange, ovipositor dark orange and sheaths dark brown (Figs 51A, B). Wings hyaline except for brown infuscation apically on the marginal and third submarginal cells of fore wing (Fig. 51B).

Head. 1.06× wider than long when viewed dorsally (Fig. 51C); face rugose except smooth with a few punctures medially above clypeus, short setae; smooth sub-antennal grooves, short setae dense laterally; frons without lateral medial carina above toruli, rugose, with scattered short setae; vertex rugulose with scattered punctures, scattered short setae; gena smooth with scattered punctures, with scattered short setae; posterior margin of head concave in dorsal view; occipital carina absent; malar space 0.24× height eye; clypeus 2.9× as wide as high, margin sinuate, distinct medial process; distance from lateral ocellus to eye margin 0.66× distance between lateral ocelli; scape 2.0× length pedicel; first flagellomere 0.7× as long as scape, 0.5× as long as second flagellomere.

Mesosoma. Propleuron rugose dorsally, pubescence long, ventro-lateral carina present; pronotum rugose, except posterior smooth; mesoscutum in lateral view angular antero-dorsally, medial and lateral lobes strigaterugose, with scattered short setae, admedial lines present (Figs 51D, E); notauli distinct, carinate, narrow and deep, shallower dorsally (Fig. 51D); scutellum and axillae strigate-rugose, scutellum anteriorly with a single deep depression; metapostnotum scrobiculate, posterior margin convex; mesopleuron rugose, with carinae dorsoposteriorly, long pubescence; mesepimeron broad, carinate, somewhat smooth dorsally; metapleuron areolate, smooth anteriorly near spiracle, with short pubescence; propodeum areolate, posterior margin smooth, with a few carinae; hind coxa rugose, with a few striations dorsally, pubescence short laterally, ovipositor guide about 2/3 rd distance along coxa, oblique, distal fringe of long setae, no setae in groove (Fig. 51F); hind trochanter imbricate, with scattered short setae; prefemur on hind leg present; hind femur imbricate, with scattered short setae; hind tibia imbricate, pubescence short, with scattered stout emergent setae; hind femur 0.8× length hind tibia; hind tibia with ventro-apical pecten of short robust spines; hind tarsomeres 1–4 with ventro-apical pecten of short robust spines, tarsomere 1, 2.6× length tarsomere 2; tarsomere 2, 1.5× length tarsomere 3; tarsomere 3, 2.2× length tarsomere 4; tarsomere 4, 0.6× length tarsomere 5; hind tarsal claw 3.0× length tarsomere 5; fore wing veins 2r-m and 3r-m largely spectral; hind wing venation incomplete, with 3 hamuli, first hamulus separated from the other 2.

Metasoma. Ovate, 1.25× length of mesosoma (Fig. 51B); T1 and T2 narrow, imbricate, T3–T8 imbricate, setae progressively denser towards tip; ovipositor 4.5 mm.

MALE. Similar to female, except T8 brown; metapostnotum broad, carinate.

Etymology. This species is named after Ken Walker, Curator of Entomology, MVMA.

Distribution. This species is known only from Mornington and Bendigo, Victoria (Fig. 67).

Biology. Nothing is known of the biology of this species.

Comments. Aulacus walkeri, A. kiwarrakensis and A. leai share a number of characters—mesosoma angular in lateral view, metasoma ovate, fore wing with brown spot apically, and hind wing venation incomplete. Aulacus walkeri can be readily separated from the other two species because it has a much longer hind tarsal claw, 3.0× compared to 0.5× length of tarsomere 5. See also key (above) for additional differences.