Diagnostic description.

Female. Body size 8.0 mm, ovipositor length 4.7 mm, fore wing length 7.3 mm (Fig. 85); colouration head and mesosoma dark brown, scape, pedicel, legs and metasoma orange, ovipositor sheaths dark brown, distinct brown infuscation of distal quarter of 1st marginal and distal half of 4th submarginal cell (Fig. 86G), hind wing veins spectral; head quadrate, width 1.0 × length, postocular space 0.4 × eye length in dorsal view (Fig. 86C), raised transverse carina above toruli absent, malar space 0.2 × height of eye (Fig. 86A); length of scape 1.5 × pedicel length, 1st flagellomere 1.3 × length of scape, 0.6 × 2nd flagellomere; mesosoma length 1.7 × height, mesoscutum in lateral view angular antero-dorsally (Fig. 86D), length 0.9 × width in dorsal view (Fig. 86E); medial lobe transverse carinae; ovipositor guide oblique, positioned distally (Fig. 86F); ovipositor sheath length 0.6 × fore wing length (Fig. 85); fore wing vein 2-Rs+M 1.4 × 1-Rs+M, three hamuli, first hamulus separated from the distal two (Fig. 86G); metasoma pyriform,T1+T2 length 1.9 × width in dorsal view.

Male. Body size (9.0–9.4) mm, similar to female.

Aulacus walkeri is superficially similar to A. smithi but can be separated by the

flagellomeres dark brown (pale-orange colouration on flagellomeres 4–8 in A. smithi), head 1.0 x length (wider, 1.5 x length in A. smithi), malar space longer 0.2 x height of eye (0.4 x height of eye in A. smithi), ovipositor 0.6 x fore wing length (longer 0.8 x fore wing length A. smithi).