Aulacus sedlaceki Jennings & Austin

Jennings, John T. & Austin, Andrew D., 2006, Aulacid wasps (Hymenoptera: Aulacidae) of New Guinea, with descriptions of five new species, Zootaxa 1365, pp. 19-35 : 25-27

Aulacus sedlaceki Jennings & Austin , sp. nov.

( Figs 1 , 7–9 )

Material examined. Holotype: ♀, " Papua New Guinea, Baiyer R. , 26.xii.1978 – 25.i.1979, J. Sedlacek " ( AEIC ).

Paratypes: Papua New Guinea: 1 ♀, same data as holotype (AEIC); 1 ♂, 50 km E Bogia , 18–22.ii.1979, J. Sedlacek ( AEIC ).

FEMALE. Length. 3.6 (3.2–4.0) mm, excluding ovipositor.

Colour. Body dark brown; head, scape, pedicel, propleuron, pronotum, mesoscutum, and fore and mid legs pale brown; hind tarsal segments 1–4 white. Wings hyaline except for a large dark brown spot on marginal, third submarginal, most of third discal and apically on subdiscal cells of fore wing.

Head. 1.40 (1.36–1.45) x wider than long in dorsal view ( Fig. 7 ); face rugose, pubescence long; indistinct subantennal groove; frons with a medial bulge above toruli, punctate to punctate-reticulate near eye margin, with scattered very short setae; vertex and gena punctate, with scattered very short setae; posterior margin of head concave in dorsal view; occipital carina absent; malar space 0.13 x eye height; clypeus 4.6 x as wide as high, margin sinuate, with distinct medial process; distance from lateral ocellus to eye margin 1.24 (1.22–1.26) x distance between lateral ocelli ( Fig. 7 ); scape 1.54 (1.42–1.67) x length pedicel; first flagellomere 0.94 x as long as scape, 0.58 (0.56–0.60) x as long as second flagellomere.

Mesosoma. Propleuron smooth except for a few punctures, pubescence long laterally, ventro-lateral carina present; pronotum without angular process, punctate; mesoscutum in lateral view rounded antero-dorsally, medial and lateral lobes coarsely strigate, with scattered short setae ( Fig. 8 ), admedial lines present; scutellum and axilla coarsely strigate ( Fig. 8 ); metapostnotum scrobiculate, posterior margin slightly curved; mesepisternum rugose, with short pubescence; mesepimeron broad, carinate; metapleuron punctate dorsally, rugose ventrally, with short pubescence; propodeum coarsely rugose laterally, smooth medially and with a median ventral carina, posterior margin smooth; hind coxa with flattened inner surface and with a slight extension on inner disto-ventral surface, extending posteriorly for a distance about equal to one-quarter length of trochanter, ovipositor guide in form of a slight depression, elongate and posteriorly-pointing, extending to tip of hind coxal extension, margins fringed with stout setae ( Fig. 9 ); hind trochanter imbricate, with scattered short setae; hind prefemur present; hind femur imbricate, with scattered short setae; hind tibia imbricate, pubescence short, with scattered stout emergent setae; hind femur 0.7 x length hind tibia; hind tibia with ventro-apical pecten of short robust spines; hind tarsal segments 1–4 with ventro-apical pecten of short robust spines, segment 1, 4.6 (3.7–5.4) x length segment 2; segment 2, 1.42 (1.50–1.33) x length segment 3; segment 3, 2.4 (1.8–3.0) x length segment 4; segment 4, 0.45 (0.33–0.56) x length segment 5; hind tarsal claw simple, 0.45 (0.33–0.56) x length segment 5; fore wing vein 2-Rs+M long, second discal cell elongate, vein 2r-m present only as a stub where it joins veins 2-M and 3-Ma, vein 3r-m largely spectral; hind wing venation incomplete, M+Cu, Cu, r-m and 2-M absent, with 3 hamuli.

Metasoma. 1.1 (1.0–1.2) x length of mesosoma; T1 and T2 narrow when viewed dorsally, glabrous except for a few shallow punctures, T3–T8 shortened, more or less ovate when viewed laterally, almost hidden by T1 and T2 when viewed dorsally; ovipositor 0.95 (0.90–1.00) mm.

MALE. Similar to female except mesoscutum in lateral view somewhat angular, propodeum areolate, T3–T8 not shortened and clearly visible when viewed dorsally.

Remarks. This species has an ovipositor guide ( Fig. 9 ) resembling that of A. emineo Jennings, Austin , & Stevens from New Caledonia ( Jennings et al. 2004c), although in A. emineo the hind coxal extension on the inner disto-ventral surface is much more pronounced than in A. sedlaceki . Similar longitudinal ovipositor guides also occur in females of the Nearctic A. burquei (Provancher) , A. digitalis Townes , A. lovei (Ashmead) , and A. pallipes Cresson , and the type species for the genus, A. striatus Jurine , from the Palaearctic (Smith pers. comm.). However, in most aulacids, including all of the Australian species examined to date ( Jennings et al. 2004 a, b; Jennings & Austin unpublished), the ovipositor guide is a groove or notch on the inner surface of the hind coxae that is more or less vertical and either medial or somewhat distal on the hind coxae (see, for example, Figs 6 , 11).

When viewed dorsally, metasomal tergites T3–T8 are short and almost hidden below T1 and T2 (fused) in both A. emineo and A. sedlaceki . In lateral view, the metasoma is somewhat compressed, and more or less ovate. In the male of A. sedlaceki , however, the metasoma is elongate such that tergites T3–T8 are clearly visible. These two species can be readily separated on the differences in the ovipositor guide, as well as differences in colouration. In A. emineo , the body is orange and head black ( Jennings et al. 2004c), whereas, the body is dark brown and head pale brown in A. sedlaceki . The form of the ovipositor guide clearly distinguishes it from other New Guinean Aulacus .

This species is named after the collector, J. Sedlacek, and is known from the Baiyer River and 50 km East of Bogia, Papua New Guinea ( Fig. 1 ). Nothing is known of its host biology.

Figures

FIGURE 1. Distribution of Aulacus and Pristaulacus species in New Guinea. ˖ = A. enaratodi;

FIGURES 4 – 9. Aaulacus enaratodi sp. nov., holotype female: 4. dorsal view of head; 5. dorsal view of mesosoma; 6. dorsal view of hind coxae; arrow indicates ovipositor guide. Aulacus sedlaceki sp. nov., holotype female: 7. dorsal view of head; 8. dorsal view of mesosoma; 9. dorsal view of hind coxae; arrow indicates ovipositor guide. Scale bars: 4 – 5 = 500 μm; 6 – 9 200 μm.