Duwalia, 2018

DUWALIA SANTOS , GEN. NOV.

( FIG. 7)

Type species: Duwalia perula sp. nov., by monotypy and present designation.

Diagnosis Duwalia gen. nov. can be distinguished from all other genera of Ateleutinae by the combination of the following characters. (1) Epicnemial carina ventrally distinct, laterally reaching about 0.7 of distance to subalar ridge. (2) Median longitudinal carina of propodeum present, though weak. (3) Hind tibia of male with sparse small bristles. (4) Hind wing vein 2-1A distinct, almost reaching wing margin. (5) Ovipositor short, OST 0.35, straight, its tip sagittate, dorsal valve with distinct teeth.

Description Body small (fore wing 4.6–5.1 mm long), moderately slender, mostly shiny ( Fig. 7A).

Head: Somewhat globose, in lateral view 1.4 × as tall as long ( Fig. 7A). Mandible relatively long, MLW 1.8, its apex distinctly narrower than base, MWW 0.6; ventral tooth slightly longer than dorsal one. Malar space moderately wide, MSM 0.8. Clypeus wide, CHW 1.8, wider at its midlength, CWW 1.8, slightly convex; clypeal margin truncate, medially straight, without teeth or tubercles, laterally slightly projected as small triangular lobe ( Fig. 7B). Antenna with 26 flagellomeres, with distinct whitish band; flagellum subapically slightly enlarged, tapered towards apex; apical flagellomere pointed, without thickened or modified setae. Supra-antennal area without horns or tubercles. Gena ventrally as wide as at its midlength. Occipital and hypostomal carinae ventrally linear, not raised as flanges, meeting at mandible base.

Thorax: Dorsal margin of pronotum regular, not swollen; outline of collar not bordered by carina; median portion of pronotum distinctly concave, forming a transverse sulcus between pronotal collar and posterior margin. Mesoscutum strongly convex, subcircular, 1.0 × as long as wide, shiny; notaulus long, reaching 0.7 of mesoscutum length, convergent, deeply impressed, its surface weakly carinulate. Lateral carina of scutellum incomplete, reaching about 0.5 of its length. Epicnemial carina ventrally distinct, laterally reaching about 0.7 of distance to subalar ridge. Sternaulus sharp and distinct on anterior 0.5 of mesopleuron, its surface distinctly crenulate. Posterior transverse carina of the mesosternum medially linear, not projected. Transverse furrow at base of propodeum 0.10 × as long as propodeum. Juxtacoxal carina indistinct. Pleural carina complete.

Propodeum: Long, 1.5 × as long as wide, shiny ( Fig. 7D). Anterior margin medially concave, laterally without teeth-like projections. Spiracle round. Anterior transverse carina vestigial. Posterior transverse carina distinct, complete, straight, sublaterally not forming distinct crests. Median longitudinal carina of propodeum distinct but fading before reaching posterior transverse carina.

Wings: Hyaline. Ramellus absent; cross-vein 1cu-a distinctly apicad to 1M+R; vein 2Cua 1.8 × as long as cross-vein 2cu-a; cross-vein 2m-cu slightly inclivous, slightly sinuous, its bulla occupying 0.4 of its length, placed anteriorly, almost touching areolet; areolet medium sized, APH 1.1, wider than long, AWH 1.6; cross-vein 3r-m spectral, almost indistinct; crossveins 2r-m and 3r-m slightly convergent, cross-vein 2r-m distinct but much shorter than 3r-m; vein 3-Rs subparallel to 3-M; vein 4-Rs slightly shorter than vein 4-M. Hind wing vein 1-M+Cu apically distinctly convex; veins Cua and 1M forming approximately right angle; vein Cua much longer than cross-vein cu-a, HW1C 1.8; veins 2-Rs and Cub distinct, reaching wing margin even if apically nebulous, apical 0.5 of Cub slightly concave; vein 2-1A distinct, almost reaching wing margin.

Metasoma: T1 moderately short, about 0.4 × as long as T2–8 combined, stout, T1LW 1.6, apex much wider than base, T1WW 3.3 ( Fig. 7F), distinctly depressed, its ventrolateral outline somewhat angled, anteriorly without lateral tooth, dorsally without distinct longitudinal striae; dorsal outline of T1 slightly and uniformly curved; spiracle of T1 placed on anterior 0.4, not prominent; dorsolateral carina distinct until spiracle; median dorsal carina entirely absent; ventrolateral carina distinct. T2 short, T2LW 0.6, apex much wider than base, T2WW 1.4; thyridium indistinct. T7–8 about as long as T5–6. Ovipositor sheath broadly truncate, slightly wider at apex than at midlength ( Fig. 7E). Ovipositor short, OST 0.35, moderately slender, straight, distinctly compressed; apex of ovipositor sagittate, with slight nodus; dorsal valve with notch-like teeth ( Fig. 7G).

Comments Duwalia is unique among Ateleutinae in having a complete epicnemial carina. In the two other genera of the subfamily, the carina is absent or indistinct at least on the mesosternum. The ovipositor is also distinct from the condition present in all other ateleutine taxa by being short (OST 0.35), having a sagittate tip and distinct teeth on the dorsal valve. Since Duwalia occurs in sympatry with Ateleute in Australia, the two genera could be mistaken for each other. Duwalia can be differentiated from Australasian species of Ateleute by having the clypeal margin laterally slightly emarginate as a small triangular lobe (vs. broadly truncate, straight); median longitudinal carina of propodeum distinct (vs. absent); male hind tibia with sparse small bristles (vs. with dense stout bristles); hind wing vein 2-1A distinct, almost reaching wing margin (vs. indistinct); and the T1 much stouter (T1LW 1.6) and more triangular (T1WW 3.3), in contrast with the slender T 1 in almost all species of Ateleute (T1LW 2.0–2.4, T1WW 2.1–2.7, usually <2.4).

E t y m o l o g y T h e g e n u s n a m e s t e m s f r o m t h e Australian aboriginal word ‘duwal’, meaning a short spear with two barbs, and also a name for a clan from the Dua moiety. The name is a reference to the short ovipositor of D. perula , with ridges on the dorsal valve. Duwalia is to be treated as a feminine noun.