Orientodromus thyridialis, Riedel, 2023

Riedel, Matthias, 2023, Contribution to the knowledge of the Ichneumoninae (Hymenoptera, Ichneumonidae) from Maritime Southeast Asia, Zootaxa 5363 (1), pp. 1-94 : 78-79

Orientodromus thyridialis nov. sp.

( Figs 34A–D )

Holotype. (♀) Malaysia: SE Sabah, nr Danum Valley Field C, WO, Malaise trap 5, c 150 m, 12.vii.–2.viii.1987, C. van Achterberg & D. Kennedy, RMNH´87 (Leiden).

Etymology. The species name refers to the very wide thyridia.

Description. ♀. Body length 5.2 mm.

Head. Flagellum with 33 flagellomeres; 1 st flagellomere 4.7 × longer than wide; widest flagellomeres about square. Temple very short, strongly and almost linearly narrowed behind eye (fig. 35B). OED 1.5 × and OOD 1.4 × ocellar diameter. Frons smooth and shining. Face with rather dense fine punctures laterally, with transverse striae medially (fig. 34A). Clypeus slightly convex, with sparse punctures; apical margin blunt, slightly bilobed. Mandible with two teeth, ventral tooth much smaller and strongly bent inwards (by 80°). Malar space 0.7 × as long as width of mandibular base. Gena with coarse sparse punctures. Genal carina reaching mandibular base.

Mesosoma . Very stout. Upper margin of pronotum ± widened and flattened. Side of pronotum smooth; epomia present. Notaulus not impressed. Mesoscutum 1.2 × wider than long, with rather dense punctures, shining. Mesopleuron coarsely and densely punctate ventrally, almost smooth dorsally; speculum smooth. Metapleuron with very sparse fine punctures; juxtacoxal carina absent. Scutellum moderately elevated, almost vertically slanting at apical margin, 1.2 × wider than long, transversely rugose, with complete lateral carina (fig. 34C). Propodeum completely carinated; without apophysis; spiracle slit-shaped (fig. 34C). Area basalis c 3.0 × wider than long, without median tubercle. Area superomedia hexagonal, slightly wider than long; anterior transverse carina reaching its middle. Hind coxa with dense punctures and large scopa apico-ventrally. Hind femur finely punctate, 3.8 × longer than wide. Claws simple. Areolet almost pointed frontally. Vein 1cu-a postfurcal by 2.0 × its width. Nervellus of hind wing vertical, intercepted at apical 0.7.

Metasoma. Oxypygous, stout. Postpetiole moderately widened, with sparse punctures, apico-medially smooth. 2 nd tergite 1.3 × wider than long. Thyridium large, slightly oblique, 2 × wider than the interval between thyridia (fig. 34D). 2 nd and 3 rd tergites coarsely rugose-punctures basally, with sparse punctures apically. Following tergites with fine sparse setiferous punctures. 2 nd to 4 th sternites with median folds. Ovipositor sheath slender, extending behind metasomal apex by length of 7 th tergite.

Colour. Black. Antenna black; scape, pedicel and basal three flagellomeres reddish ventrally; flagellomeres 7–12 ivory dorsally. Ivory are palps, mandible except tooth, clypeus, face, gena, orbits (except interruption on outer orbit), frontal and upper margins of pronotum, subtegular ridge, short oval paramedian spots on mesoscutum, scutellum and postscutellum, wide ventral stripe and posterior margin of mesopleuron, upper division and apical spot on metapleuron, area dentipara of propodeum, petiole, apical bands on 1 st to 4 th tergites, posterolateral spots on 5 th tergite and small apical spot of 7 th tergite. Fore and mid legs including coxae and trochanters ivory, fore and mid femora and tibiae with reddish stripes dorsally; hind coxa red, black apically and with ivory spot dorsally; hind trochanter brown; hind femur red, black basally and apically; hind tibia brown, with ivory subbasal spot; hind tarsus except black distal tarsomere ivory. Wings hyaline; pterostigma brown.

♂ unknown.

Distribution. Only known from Borneo.

Figures

FIGURE 34. Orientodromus thyridialis n. sp. HT ♀. A face, frontal view, B head, dorsal view, C propodeum, dorsal view, D basal tergites, dorsal view.