Ichneumon giganteus, Riedel, 2023

Riedel, Matthias, 2023, Five new Oriental species of the genus Ichneumon LINNAEUS (Hymenoptera, Ichneumonidae, Ichneumoninae), Linzer biologische Beiträge 55 (1), pp. 47-60 : 49-51

Ichneumon giganteus nov.sp. ( Figs 5-8 )

M a t e r i a l e x a m i n e d: Holotype: (♀) Laos, Hua Phan Prov., Phon Pan (Mt.), Ban Saleui (Village), 20°13´30´´N 103°59´26´´E, 1350-1900 m MSL, 03- 05.06.2009, leg. C. Holzschuh, and many locals (Linz). P a r a t y p e s: (♁) Laos, Hua Phan Prov., Ban Saleui, Phon-Pan-Mt., 20°13´30´´N 103°59´26´´E, 1350-1900 m, 03.05.2011, leg. C. Holzschuh & natives (Linz); (♁) Laos, Hua Phan Prov., Ban Saleui, Phon-Pan-Mt., 20°13´30´´N 103°59´26´´E, 1350- 1900 m, 07.05.2011, leg. C. Holzschuh & natives (Linz).

E t y m o l o g y: The species name refers to the very large size.

D e s c r i p t i o n: ♀. Body length 30 mm. Flagellum slender and slightly lanceolate, with 56 flagellomeres; 1 st flagellomere 2.5 × longer than wide, about 15 th flagellomere square, widest flagellomeres 1.2 × wider than long. Head punctate. Temple strongly and concavely narrowed behind eye. Occipital carina lamelliform. OED 1.2 × ocellar diameter. Apical margin of clypeus almost straight. Malar space 0.4 × as long as width of mandibular base. Mandible unmodified and with two teeth; ventral tooth distinctly smaller than dorsal tooth. Genal carina reaching hypostomal carina far from mandibular base.

Mesosoma covered with whitish setae. Notaulus strongly impressed in frontal half of mesoscutum. Mesoscutum with fine superficial punctures and finely granulated, dull. Mesopleuron and metapleuron punctate, shining. Scutellum longer than wide, moderately elevated, without lateral carina. Area superomedia slightly elevated, hexagonal, slightly longer than wide, rugose; anterior transverse carina (costula) reaching its middle. Area externa of propodeum with fine oblique striation; area petiolaris with strong lateral carina and transverse striation. Hind coxa densely punctate, with very small reddish scopa. Hind femur slender, densely punctate, 5.6 × longer than wide. Tarsi slender; 3 rd mid tarsomere 2.0 × longer than wide. Claws simple. Areolet longer than wide, frontal distance between veins 2rs-m and 3rs-m 2 × their width. Vein 1cu-a strongly postfurcal.

Metasoma strongly oxypygous. Lateral field of postpetiolus 0.8 × as wide as median field, median field strongly aciculate, with c. 20 fine longitudinal stripes. Thyridium 1.2 × wider than the interval between thyridia, the interval about as wide as median field of postpetiole. 2 nd tergite 1.1 × wider than long. 2 nd to 4 th tergites finely punctate; 2 nd tergite ± aciculate medially; 5 th tergite with very superficial punctures; 5 th to 7 th tergites shining. Ovipositor sheath slightly extending behind metasomal apex.

Color: black. Ivory are ventral stripes on flagellomeres 2-18, palps, mandibular base, side of clypeus, triangular spot on facial orbit, frontal and vertical orbits, gena and outer orbit in ventral half, scape and pedicel ventrally, propleuron, collar, upper margin and ventral spot on pronotum, spot on tegula, subtegular ridge, two longitudinal paramedian stripes on mesoscutum, smaller spot on mesopleuron frontal to epicnemial carina and larger spot on central mesopleuron, posteromedian spot on mesosternum, scutellum and postscutellum, upper division and spot on metapleuron, area dentipara, posterolateral marks on all tergites, spots on fore and mid coxae, all trochanters and trochantelli, apical 1/3 of all femora, tibiae and tarsi, dorsal and ventro-apical spots on hind coxa, apical 1/3 of hind tibia, fore and mid metatarsi apically and rings of other fore and mid tarsomeres, apical half of hind metatarsus, and 2 nd to 5 th hind tarsomeres mainly. Wings with brownish tinge; pterostigma blackish.

♁: Body length 23-29 mm. Flagellum slender and bristle-shaped, with 48-51 flagellomeres. Tyloids on flagellomeres 12-20, long-oval. Hind femur 5.4 × longer than wide. Fore metatarsus without apical tooth. 2 nd tergite 1.1 × longer than wide. 2 nd to 4 th tergites finely punctate, aciculate medially, ± dull; 5 th tergite with aciculation in basal 1/3 only. 6 th and 7 th tergites shining, with superficial punctures.

Color: black. Tyloids black. Ivory are dorsal stripes on flagellomeres 1-21, clypeus and face entirely, frontal stripes on fore and mid femora, tibiae and tarsi, dorsal and ventro-apical spots on hind coxa, apical 1/4 of hind femur, apical 1/3 of hind tibia, apical half of hind metatarsus, and 2 nd to 5 th hind tarsomeres mainly. Wings hyaline, pterostigma blackish. Coloration otherwise as described for the ♀.

R e m a r k s: This new species represents one of the largest Ichneumonines from the Oriental region. It is related to Ichneumon leucogigas HEINRICH, 1965 , but differs by two longitudinal paramedian stripes on mesoscutum, posterolateral yellow marks of all tergites including the 7 th, black prescutellar ridge and different coloration of the propodeum.

D i s t r i b u t i o n: Only known from Laos.

Figures

Figs 5-8: Ichneumon giganteus nov.sp.: (5) face of HT, (6) head of PT, (7) propodeum of PT, (8) basal tergites of PT.