(Figs 26–32, 62)

Material examined. Holotype female (MNHN) PNG, Madang Prov., Mt. Wilhelm (-5.720874, 145.2695), 1200 m, 25–26.V.2013, leg. Sam et al., Plot 3, understorey; MAL-MW1200’C-13/16-d13, P4809-20963.

Paratypes. PNG, Madang Prov.: 1 ♀ (MNHN) Mt. Wilhelm (-5.720874, 145.2695), 1200 m, 30–31.X.2012, leg. Philip, Alois, Novotny & Leponce, Plot 4, understorey; MAL-MW1200D-06/16-d06, P1831-11314 (apex of ovipositor broken). 1 ♀ (ZISP) same data, but 14–15.V.2013, Plot 4, leg. Sam et al.; MAL-MW1200’D-02/16-d02, P4814-20880. 1 ♀ (MNHN) same data, but 28–29.V.2013, Plot 1; MAL-MW1200’A-16/16-d16, P4780-20977.

Description. Female. Body length 6.3 mm. Fore wing length 4.0 mm.

Head roundly constricted behind eyes in dorsal view (Fig. 27); gena 0.4–0.45× as long as eye width. Clypeus (Fig. 28) broad, lenticular, about 2.5× as broad as long, slightly convex in lateral view, separated from face by broad impression, smooth, with distinct punctures in upper 0.7. Mandible slender, slightly constricted basally, with upper tooth 2.5× as long as lower tooth. Malar space almost as long as basal mandibular width (Fig. 29). Antennal flagellum (Fig. 26) filiform, with 19–21 flagellomeres (21 in holotype); subbasal flagellomeres 1.5–1.7× and subapical flagellomere 1.2–1.4× as long as broad; flagellomeres 4 to 8 bearing subapical finger-shaped structures on outer surface (Fig. 29). Face weakly and evenly convex. Face and frons with strong and very dense punctures; face more or less smooth between punctures centrally and finely granulate peripherally, frons entirely finely granulate. Vertex finely punctate, smooth and shining between punctures; punctures are dense anteriorly and sparse posteriorly (near occipital carina). Gena smooth and shining, with fine and moderately dense punctures. Occipital carina mediodorsally obliterated (Fig. 27).

Mesoscutum with strong and dense punctures (distance between punctures mostly shorter than diameter of one puncture) on shallowly granulate and dull background. Notaulus with longitudinal wrinkle (or irregular wrinkles) on anterolateral side of mesoscutum. Scutellum with lateral longitudinal carinae present in basal 0.4–0.5. Mesopleuron with strong and dense punctures (distance between punctures mostly shorter than diameter of one puncture), smooth between punctures centrally. Foveate groove extending in anterior half of mesopleuron, strongly oblique, deep and very broad, with long transverse wrinkles reaching epicnemial carina (Fig. 29). Upper end of epicnemial carina evenly converging with anterior margin of mesopleuron, without abrupt apical curvature. Propodeum with basal keel which is 0.4–0.5× as long as apical area. Dorsolateral area of propodeum with strong and dense punctures (distance between punctures mostly shorter than diameter of one puncture), smooth between punctures, sometimes with vertical wrinkles in lower part. Propodeal spiracle enlarged, separated from pleural carina by 2.0–2.5× diameter of spiracle (Fig. 29). Apical area distinctly impressed along midline, rounded or slightly pointed anteriorly (Fig. 30); apical longitudinal carinae complete, though sometimes weak or evanescent anteriorly.

Fore wing with second recurrent vein (2m-cu) postfurcal, with short bulla in anterior part. First abscissa of radius (Rs+2r) straight, much longer than width of pterostigma. First and second sections of radius (Rs+2r and Rs) meeting at right angle. Intercubitus (2rs-m) slightly thickened, long, 1.5× to almost twice as long as abscissa of cubitus between intercubitus and second recurrent vein (abscissa of M between 2rs-m and 2m-cu) (Fig. 62). Metacarpus (R1) reaching tip of the wing. Second abscissa of postnervulus (Cu&2cu-a) present. Hind wing with nervellus (cu1&cu-a) nearly vertical. Legs slender; tarsal claws slender, not pectinate.

First tergite 5.4× as long as posteriorly broad, round in cross-section, entirely smooth, without any vestiges of glymma, weakly and gradually widened from base to apex in dorsal view, with petiole not separated from postpetiole (Fig. 31); upper margin of tergite, in lateral view, straight or very weakly arcuate in basal 0.5–0.6 and distinctly arcuate in apical 0.4–0.5 (Fig. 26). Second tergite about 2.5× as long as anteriorly broad. Thyridial depression shallow, very long, with posterior end very narrow and indistinct. Ovipositor weakly bent upwards over its total length, with shallow dorsal subapical depression (Fig. 32); sheath about 1.5× as long as first tergite.

Head and mesosoma dark reddish brown or black. Palpi yellow. Mandible (teeth reddish black) and lower 0.3 of clypeus brownish yellow or yellow-brown. Scape and pedicel of antenna brownish yellow, dorsally brown; flagellum uniformly black. Tegula brown or dark brown. Pterostigma brown. Wings slightly infumate with brown. Legs (Fig. 26) predominantly yellowish brown with brown and dark brown markings on coxae and femora; tibiae and tarsi more or less infuscate. First tergite dark reddish brown to almost black. Metasoma posterior to first tergite predominantly dark brown to brownish black anteriorly, brown to brownish yellow ventrally and posteriorly (Fig. 26).

Male. Unknown.

Variation. Basal keel of propodeum sometimes anteriorly or entirely obliterated.

Etymology. The species is named after the seventh letter of the Greek alphabet (eta).

Distribution. Papua New Guinea.

Comparison. Diaparsis eta sp. nov. most easily differs from all other PNG species of Diaparsis having notaular wrinkle by the head with occipital carina obliterated mediodorsally (Fig. 27). The new species is also characterized by unusually long intercubitus (2rs-m) in the fore wing (Fig. 62).