Achaius sabahensis Riedel 2023, nov. sp.
Creators: name: Riedel, Matthias
Publisher: name: Zenodo
Year: 2023
Subjects: Biodiversity
Taxonomy
Animalia
Arthropoda
Insecta
Hymenoptera
Ichneumonidae
Achaius
Achaius sabahensis

description: Achaius sabahensis nov. sp.
(Figs 2A–D)
Holotype. (♀) Malaysia: Sabah, Kinabalu Park Head Q., 8–11.iii.1987, c 1600 m, Malaise trap 1, C. van Achterberg, RMNH´87 (Leiden).
Description. ♀. Body length 10.5 mm.
Head. Flagellum with 40 flagellomeres, slender, almost filiform; 1 st flagellomere 3.7 × longer than wide, widest flagellomeres 1.2 × longer than wider. Temple rather long, distinctly and linearly narrowed behind eye (fig. 2B). OED 1.0 × and OOD 1.1 × ocellar diameter. Frons smooth ventrally, transversely rugose-punctate dorsally. Face densely punctate, shining. Clypeus almost flat, with sparse punctures; apical margin sharp and slightly concave (fig. 2A). Mandible long, with two teeth, ventral tooth smaller than dorsal one. Malar space 1.2 × as long as width of mandibular base. Gena with sparse fine punctures. Genal carina reaching hypostomal carina away from mandibular base.
Mesosoma. Side of pronotum densely punctate dorsally, with irregular rugae ventrally. Notaulus indistinct. Mesoscutum finely and densely punctate, slightly shining. Mesopleuron densely punctate and finely striate ventrally, densely punctate dorsally; speculum smooth. Metapleuron rugose-punctate; juxtacoxal carina present. Scutellum moderately elevated, about as long as wide, with fine sparse punctures; without lateral carina. Propodeum (fig. 2C) rugose, with distinct blunt apophysis; spiracle slit-shaped. Area basalis not carinated, without median tubercle. Area superomedia almost rectangular, 1.4 × longer than wide; costula absent. Hind coxa densely punctate, without scopa. Hind femur slender, densely punctate, 5.1 × longer than wide. Claws simple. Areolet pentagonal, frontal distance between veins 2rs-m and 3rs-m 5 × their diameter. Vein 1cu-a postfurcal by 3.0 × its width.
Metasoma. Strongly amblypygous; hypopygium unmodified, with fine setae, reaching metasomal apex. 2 nd and 3 rd sternites with median folds. Postpetiole moderately widened, without latero-median carina; median field moderately elevated, finely rugose; lateral field punctate. Gastrocoelus impressed, without ridges. Thyridium very small, oblique, 0.2 × as wide as the interval between thyridia (fig. 2D). 2 nd tergite as long as wide, finely rugose and slightly aciculate in basal half, granulate apically, ± dull. Following tergites finely granulate, shining. Ovipositor sheath not reaching behind metasomal apex.
Colour. Black. Flagellum black; flagellomeres 8–12 brownish dorsally. Face and gena with dark reddish suffusion; frontal orbit with reddish-yellow stripe. Hind edge of pronotum, tegula, subtegular ridge, central spot of mesoscutum and scutellum reddish. Tergites dark reddish-brown; 7 th tergite with ivory median spot. Legs black; fore and mid femora and tibia reddish-yellow stripes frontally; hind tibia diffusely reddish-brown sub-basally. Wings hyaline; pterostigma blackish.
♂ unknown.
Remarks. This new species runs to Achaius flavorufus Heinrich, 1965 in the key of the Oriental Achaius species (Heinrich 1965: 111–112), but differs from all known Oriental species by the strong reduction of pale coloration.
Distribution. Only known from Borneo.
description: Published as part of Riedel, Matthias, 2023, Contribution to the knowledge of the Ichneumoninae (Hymenoptera, Ichneumonidae) from Maritime Southeast Asia, pp. 1-94 in Zootaxa 5363 (1) on pages 9-11, DOI: 10.11646/zootaxa.5363.1.1, http://zenodo.org/record/10146851