Aulacus obcordellus Jennings & Parslow, 2018

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Aulacus obcordellus Jennings & Parslow 2018: 69.—ABRS 2019 [on-line checklist].

Aulacus scitulus Jennings & Parslow 2018: 79.—ABRS 2019 [on-line checklist]. syn. nov.

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Figure 67. Aulacus obcordellus Jennings & Parslow, female, lateral habitus. Scale bar = 1.00 mm.

Figure 68. Aulacus obcordellus Jennings & Parslow, female, A, lateral head; B, frontal face; C, dorsal head; D, lateral mesosoma; E, dorsal mesosoma; F, ovipositor guide; G, fore wing. Scale bar = 1.00 mm.

Diagnostic description.

Aulacus obcordellus is a distinctive species that is easily separated from other Australian species based on the combination of head shape with distinctive pointed transverse carina above toruli, medial lobe of mesonotum heart shaped in dorsal view, colouration orange body, black head with large cream coloured section of flagellomeres, fore wing vein 2r-m absent.

Female. Body size 8 (6.4–9.4) mm, ovipositor length 6 (4.8–7.0) mm, fore wing length 6.9 (5.7-6.9) mm (Fig. 67); colouration body orange, except head black except variable amounts of orange on sub-antennal grooves. antenna black except flagellomeres 5–7 cream-coloured, ovipositor sheaths black except apex orange; wings hyaline with a brownish tinge (Fig. 68G), hind wing veins spectral; head shape quadrate, width 1.6 (1.4–2.0) × length, postocular space 0.4 (0.4) × eye length in dorsal view (Fig. 68C), raised transverse carina above toruli, malar space 0.4 (0.3–0.4) × height of eye (Fig. 68A); length of scape 1.7 (1.7–1.9) × length of pedicel, 1st flagellomere 1.5 (1.3–1.5) × length of scape, 0.6 (0.5–0.6) × 2nd flagellomere; mesosoma length 1.8 (1.7–1.8) × height, mesoscutum in lateral view angular antero-dorsally (Fig. 68D); mesoscutum length 0.7 (0.7) × width in dorsal view (Fig. 68E); medial lobe with transverse carinae; ovipositor guide absent (Fig. 68F); ovipositor sheath length 0.9 (0.8–0.9) × fore wing length (Fig. 67); 2-Rs+M 1.3 (1.2–1.3) × 1-Rs+M, fore wing vein 2r-m absent, three hamuli, equidistant (Fig. 68G); metasoma clavate, T1+T2 length 1.6 (1.6–1.9) × width in dorsal view.

Material examined.

Holotype. AUSTRALIA – Tasmania • ♀, "Arve Valley, ex Nothofagus cunninghamii, Host: Nascoides quadrinotata, coll. 27.1.[19]83 R. Bashford” (TMAG).

Paratypes. AUSTRALIA – Queensland • 1 ♀, Mt Glorious, Dec. 12, (AEI). – Victoria • 3 ♀♀, Mt. Dandenong, 200 m. 11-22.ii ( no year) (AEI). – Tasmania • 1 ♀, Frenchmans Cap, Franklin River, 14-21.Feb. (AEI) • 1♀, Franklin River, 22.Feb.–26 Mar. (AEI).

Other material examined.

AUSTRALIA – Queensland • 1 ♀, Holotype of Aulacus scitulus “ex Malaise trap, 16 km Davies Ck Rd Mareeba NEQ, 6Nov -2Dec 1984, Storey & Halfpapp” (ASCU).

Figure 67. Aulacus obcordellus Jennings & Parslow, female, lateral habitus. Scale bar = 1.00 mm.

Distribution.

This species has been collected from widely separated localities across eastern and south-eastern Australia (Fig. 96).

Biology.

The holotype specimen has been reared from Nothofagus cunninghamii (Nothofagaceae) infested with Nascioides quadrinotatus (Buprestidae), originally recorded as Nascoides quadrinotata.

Notes.

The type specimens of A. obcordellus and A. scitulus show only minor differences in coloration and sculpturing, as noted by Jennings et al. (2018). After examination of available material, we are confident in synonymising A. scitulus with A. obcordellus, primarily due to distinctive features such as the pointed transverse carina above the toruli, the heart-shaped medial lobe of the mesonotum in dorsal view, and the absence of an ovipositor guide.