Losgna rufobasalis, Riedel, 2023

Riedel, Matthias, 2023, Contribution to the knowledge of the Ichneumoninae (Hymenoptera, Ichneumonidae) from Maritime Southeast Asia, Zootaxa 5363 (1), pp. 1-94 : 70-71

Losgna rufobasalis nov. sp.

( Figs 30A–D )

Holotype. (♀) Indonesia: N Sumatra, Ketambe , 400 m, Mal. trap, near edge rainforest, xi.1995, Y. van Nierop & C. van Achterberg, RMNH´99 (Leiden).

Paratype. (♂) Indonesia: N Sumatra, Ketambe , 400 m, Mal. trap, near edge rainforest, iii.1995, Y. van Nierop & C. van Achterberg, RMNH´99 (Leiden) .

Etymology. The species name refers to the reddish area basalis.

Description. ♀. Body length 9.5 mm.

Head. Flagellum with 44 flagellomeres, moderately lanceolate; 1 st flagellomere 2.4 × longer than wide, about 12 th flagellomere square, widest flagellomeres 1.8 × wider than long. Temple rather short, strongly and roundly narrowed behind eye, dorsally 0.4 × as long as eye (fig. 30B). OED 1.3 × and OOD 0.8 × ocellar diameter. Frons smooth and shining, with very sparse punctures. Face rather densely punctate. Clypeus almost flat, with sparse punctures; apical margin blunt, slightly bulging medially (fig. 30A). Malar space 0.8 × as long as width of mandibular base. Gena with very sparse punctures. Genal carina reaching hypostomal carina at mandibular base.

Mesosoma . Notaulus distinct in frontal 0.4 of mesoscutum. Mesoscutum densely but superficially punctate, shining. Mesopleuron with superficial punctures, shining, with short coarse striae at posterior margin. Metapleuron rugose-punctate; juxtacoxal carina present. Scutellum almost flat, slightly longer than wide, with sparse punctures and complete lateral carina. Propodeum (fig. 30C) completely carinated, without apophysis. Area basalis with median tubercle. Area superomedia large, about as long as wide, with coarse irregular striae; costula reaching at 3/10 of its length. Hind coxa with dense punctures, without scopa. Hind femur 4.0 × longer than wide. Claws simple. Areolet pentagonal, frontal distance between veins 2rs-m and 3rs-m 2.0 × their diameter. Vein 1cu-a antefurcal by 1.0 × its width.

Metasoma. Oxypygous; 2 nd to 4 th sternites with median folds. Postpetiole distinctly widened, almost smooth with fine very sparse punctures; median field not separated. Gastrocoelus small, longer than wide, with some ridges. Thyridium very small, strongly oblique, 0.2 × as wide as the interval between thyridia. 2 nd tergite about as wide as long, with distinct paramedian impressions (fig. 30D). 2 nd tergite with coarse longitudinal rugose-punctate striation. 3 rd tergites rugose-punctate in basal half; with fine dense punctures and shining apically; following tergites with fine punctures, shining. Ovipositor sheath rather long, extending distinctly behind metasomal apex.

Colour. Black. Ivory are flagellomeres 8–17 dorsally, palps, mandible except teeth, clypeus, face, gena, narrow frontal orbits, spot on vertex, scape ventrally, spot of subtegular ridge, prescutellar ridge, scutellum laterally and apically, spot of postscutellum, spot in front of propodeal spiracle and posterolateral spot of propodeum around outer edge of area dentipara, petiole, small posterolateral spots of postpetiole and 2 nd tergite (fig. 30D), wide apical band of 6 th tergites and entire 7 th and 8 th tergites. Collar and upper margin of pronotum, tegula, ventral spot of mesopleuron and area basalis ± reddish. Legs red; fore and mid coxae and trochanters ivory; hind tibia and tarsus black. Wings hyaline; pterostigma blackish, paler basally.

♂: Body length 10.0 mm. Flagellum with>34 flagellomeres (tips broken off); 1 st flagellomere 2.6 × longer than wide. Tyloids on flagellomeres 11–19, long-oval, maximally 0.6 × as long as their flagellomeres. OED 1.5 × and OOD 1.0 × ocellar diameter. Malar space 0.8 × as long as width of mandibular base. Genal carina reaching mandibular base. Notaulus short, impressed in frontal 0.2 of mesoscutum. Area superomedia 2.0 × wider than long, with longitudinal striation. Hind femur 4.5 × longer than wide. 2 nd tergite 1.1 × longer than wide. Apical margin of hypopygium rounded. Otherwise as described for the ♀.

Colour. As in ♀. Different are: flagellum reddish-brown proximally, infuscate distally; flagellomeres 11–19 with ivory rings. Frontal orbit up to vertex, spot of collar, upper margin and ventral edge of pronotum, spot on tegula and wide stripe on ventral mesopleuron, 6 th tergite mainly and 7 th tergite and paramere entirely ivory. 1 st to 3 rd tergites with small posterolateral ivory spots; 2 nd tergite with wide reddish-yellow apical band. Hind trochantellus brownish; hind tibia brownish, hind tarsus black.

Remarks. This new species is closely related to Losgna cariniscutis (Cameron, 1905) and probably represents a subspecies of that species. The ♂ of this species differs from the ♂ of Losgna cariniscutis by the ivory ring of flagellum, apical reddish-yellow band of 2 nd tergite and wide ivory stripe on ventral mesopleuron.

Distribution. Only known from Sumatra.

Figures

FIGURE 30. Losgna rufobasalis n. sp. HT ♀. A face, frontal view, B head, dorsal view, C propodeum, dorsal view, D basal tergites, dorsal view.