Stirexephanes rufopetiolaris, Riedel, 2023

Riedel, Matthias, 2023, Contribution to the knowledge of the Ichneumoninae (Hymenoptera, Ichneumonidae) from Maritime Southeast Asia, Zootaxa 5363 (1), pp. 1-94 : 87-89

Stirexephanes rufopetiolaris nov. sp.

( Figs 39A–D )

Holotype. (♀) Indonesia: Sumatera Barat, Joron Akar Gadang, Simpang Tanjung Nam IV, Danau Kembar, Solok , 1.0579°S 100.697°E, 1412 m, 13-May-2016, H. Hamid, COI 0, INDOBIOSYS-CCDB23977-G04 ( ZSM).

Paratype. (♂) Malaysia: SW Sabah, nr Long Pa Sia (West), c. 1010 m, 25.xi.–8.xii.1987, Mal. trap 1 b, C. van Achterberg (Leiden) ; Indonesia: Sumatera Barat, Lahan basah, Andalas University, Bukit , Karamuntiang , Padang , 0.9087°S 100.478°E, 400 m, 23–Jan–2016, H. Hamid, INDOBIOSYS-CCDB23977-A05 ( ZSM) .

Etymology. The species name refers to the reddish 1 st tergite.

Description. ♀. Body length 8.1 mm.

Head. Flagellum with 30 flagellomeres, slightly lanceolate; 1 st flagellomere 3.2 × longer than wide, 9 th flagellomere square, widest flagellomeres 1.4 × wider than long, apical flagellomere very blunt. Temple very short, strongly and linearly narrowed behind eye. OED 1.0 × and OOD 0.6 × ocellar diameter. Vertex finely granulated. Frons shining, finely granulate and with superficial punctures dorsally. Face densely punctate, with some transverse rugae medially. Clypeus large, almost flat, with sparse punctures; apical margin blunt and almost straight (fig. 39A). Mandible long and rather slender, with two teeth; ventral tooth much smaller and slightly bent inwards. Malar space 1.0 × as long as width of mandibular base. Gena with sparse fine punctures. Genal carina reaching hypostomal carina away from mandibular base.

Mesosoma . Notaulus distinctly impressed in frontal fourth of mesoscutum. Mesoscutum finely and densely rugose-punctate, dull. Sternaulus distinctly impressed in frontal half of mesopleuron. Mesopleuron finely rugose-punctate and ± striate; speculum partly smooth (fig. 39B). Metapleuron finely rugose and striate; juxtacoxal carina present. Scutellum slightly elevated, with lateral carina in basal 0.8, slightly longer than wide, with sparse punctures. Propodeum completely carinated, with blunt short apophysis (fig. 39C); spiracle slit-shaped. Area basalis trapezoid, wider than long, without median tubercle. Area superomedia hexagonal, 1.3 × longer than wide; costula reaching at basal 0.35 of its length. Hind coxa with fine dense punctures, without scopa; hind femur densely punctate, 4.3 × longer than wide. Claws simple, strongly bent apically. Areolet pentagonal, frontal distance between veins 2rs-m and 3rs-m 2.0 × their diameter. Vein 1cu-a interstitial.

Metasoma (fig. 39D). Oxypygous. Petiole about as wide as high. Postpetiole slightly widened, without latero-median carina; median field not separated, finely granulate; lateral field finely punctate. Gastrocoelus small, longer than wide, with fine ridges. Thyridium small, comma-shaped, 0.3 × as wide as the interval between thyridia. 2 nd tergite 1.1 × longer than wide. 2 nd and 3 rd tergites finely and densely rugose-punctate, dull. Following tergites finely granulate, slightly shining. 2 nd to 5 th sternites with median folds. Ovipositor sheath narrow, reaching behind metasomal apex by length of 7 th tergite.

Colour. Black. Flagellum black, flagellomeres 6–13 ivory dorsally. Palps ivory. Median spot of mandible, lateral margin of clypeus and scape ventrally reddish. Mesosoma black; scutellum, postscutellum, posterior half of mesopleuron, metapleuron and propodeum red. 1 st tergite red; following tergites black. 2 nd tergite diffusely reddish in posterior half and with narrow yellow apical margin. Apical band of 6 th tergite and 7 th tergite mainly ivory (fig. 40D). Fore and mid coxae and all trochanters ivory; hind coxa black ventrally, red dorsally. Fore and mid femora and tibiae and fore tarsus reddish; mid tarsus brown. Hind femur, tibia and tarsus black; hind tibia with small yellowish spot basally. Wings almost hyaline; pterostigma ochreous.

♂. Body length 10.8–11.6 mm. Flagellum with 34–35 flagellomeres, bristle-shaped; 1 st flagellomere 3.2–3.3 × longer than wide, distal flagellomeres slightly nodose. Tyloids on flagellomeres 6–13, linear, maximally 0.8× as long as their flagellomeres. OED 1.1 × and OOD 0.9 × ocellar diameter. Malar space 0.6 × as long as width of mandibular base. Notaulus impressed in frontal 0.2 of mesoscutum. Mesoscutum with fine dense and ± superficial punctures, dull. Mesopleuron and metapleuron densely and superficially punctate, not striate. Hind femur 4.2–4.6 × longer than wide. 2 nd tergite 1.1 × longer than wide. Hypopygium unmodified, apical margin slightly rounded. Structure otherwise as described for the ♀.

Colour. Black. Flagellum black, basal flagellomeres ± reddish, flagellomeres 11/12–18/19 ivory dorsally. Palps, mandible except teeth, clypeus, face, gena, frontal orbit, sometimes outer orbit and scape ventrally ivory. Mesosoma black; propleuron, and sometimes collar and spot of tegula ivory. Scutellum ±, postscutellum, tegula, sometimes posterior half of mesopleuron, metapleuron and propodeum red. 1 st tergite red; 2 nd tergite black, reddish or yellowish in apical 0.4–0.5. Following tergites black; sometimes 3 rd and 4 th tergites with narrow yellowish apical bands; apical band of 6 th tergite, 7 th tergite and paramere ivory. Fore coxa and fore and mid trochanters ivory; mid coxa reddish-yellow, with apical ivory spot; hind coxa red, diffusely infuscate ventrally. Fore and mid femora and tibiae and fore tarsus reddish or ochreous; mid tarsus brown; hind leg black; hind tibia with external ivory stripe, sometimes with basal ivory spot. Pterostigma ochreous.

Remarks. This new species differs from all other known Stirexephanes species by the bicolored mesosoma and red 1 st tergite.

Distribution. Known from Borneo and Sumatra.

Figures

FIGURE 39. Stirexephanes rufopetiolaris n. sp. HT ♀. A face, frontal view, B mesosoma, lateral view, C propodeum, dorsal view, D metasoma, dorsal view.