Chelonus (Carinichelonus) siangensis sp. nov.

(Figures 3–4)

urn:lsid:zoobank.org:act: D5E25598-C528-4791-95FE-E62CFA621996

Material examined. Holotype, female, INDIA: Arunachal Pradesh, Komsing, 28°25’3592 N, 95°00’0628 E, 1208 m.a.s.l., 2.v.2022, coll. A. P. Ranjith (AIMB) . Paratypes, 1 male, INDIA: Arunachal Pradesh, Pangin, 28°19’2627 N, 95°02’1793 E, 1259 m.a.s.l., 1.iv.2022, coll. A.P. Ranjith (AIMB) .

Description. Holotype, female, length of body 5.2 mm, fore wing 3.5 mm.

Head.Antenna with 16antennomeres, subapical antennomeres broadened, shorter than basal antennomeres, apical antennomeres narrow (Fig. 3A); third antennomere 1.2 × longer than fourth; third, fourth and terminal antennomeres 4.3 ×, 3.7 × and 3.6 × longer than wide, respectively; head transverse (Fig. 3B), in dorsal view roundly contracted behind eyes (Fig. 3D); OOL: OD: POL= 4.7: 1.0: 2.9; longitudinal diameter of eye 1.4 × height of temples; vertex coarsely longitudinally striate (Fig. 3D); frons distinctly concave, longitudinally striate, smooth posteriorly with mid and lateral longitudinal carinae (Figs 3C–D); occiput longitudinally striate (Fig. 3D); temple longitudinally striate (Fig. 3E); face coarsely reticulate-rugose with longitudinal short medio-posterior groove (Fig. 3B); clypeus flat and densely punctate, smooth and shining (Fig. 3B); length of malar space 2.7 × basal width of mandible.

Mesosoma. Length of mesosoma 1.4 × its height; pronotum rugose-reticulate laterally (Figs 3E–F); mesoscutum areolate-rugose (Fig. 4A); middle lobe of mesoscutum smooth and punctate medially (Fig. 4A); notauli impressed as large pits (Fig. 4A); lateral lobes of mesoscutum rugose posteriorly (Fig. 4A); transverse suture distinct, deep (Fig. 4A); scutellar sulcus divided by three carinae (Fig. 4A); scutellum irregularly punctate, sparsely setose, with crenulate groove laterally (Fig. 4A); mesopleuron evenly convex, coarsely reticulate-rugose, setose (Fig. 3F); metanotum crenulate with distinct midlongitudinal carina (Fig. 4B); propodeum with medial and lateral tubercles, coarsely reticulate-rugose, with basal areola and two pairs of areolae medially, transverse carina distinct and complete (Fig. 4B).

Wings. Fore wing infuscate apical half (Fig. 4F); length of fore wing 2.5 × its width; length of marginal cell 1.3 × pterostigma; vein 2-Rl present, short (Fig. 4F); vein r shorter than 3-SR (Fig. 4F); r: 3-SR: SRl = 1.0: 2.3: 5.8; SRl straight (Fig. 4F); parastigma distinctly swollen; 1-CU1: 2-CU1= 1.0: 6.8; vein CUlb present (Fig. 4F).

Legs. Hind coxa smooth, densely short setose (Figs 4C, E); hind femur robust; length of hind femur, tibia and basitarsus 3.4 ×, 4.0 × and 4.0 × their maximum width, respectively; mid and hind tibia with numerous short, pointed spines apical half (Figs 4C, E).

Metasoma. Metasomal carapace elongate-oval in dorsal view, coarsely reticulate-rugose, longitudinally striate antero-medially with a pair of parallel sided midlongitudinal carinae basally (Fig. 4D); length of carapace 2.3 × its maximum width in dorsal view; carapace without undulating lamella laterally (Figs 4C, E); ventral cavity closed apically, bordered with crenulate lamellae (Fig. 4E); ovipositor long, slender (Fig. 4E) and the ovipositor sheath 0.07 × as long as fore wing, 0.2 × as long as hind tibia.

Colour. Black except eyes, ocelli grey, maxillary and labial palps, antenna, tegula, wing veins, pterostigma dark brown, fore femur apically, hind tibial spurs, carapace subbasally, ventral lamella yellow.

Male (Fig. 5). Similar to female except the size, body length 4.9 mm; metasomal carapace with a pair of yellow spots near basal midlongitudinal carinae and baso-lateral yellow area; carapace with a pair of reddish yellow circular spot above apex of ventral opening.

Biology. Unknown.

Distribution. India (Arunachal Pradesh)

Etymology. The species is named after the Siang Valley, which is part of the Eastern Himalayas Biodiversity Hotspot, where the type locality is situated.

Comparative diagnosis. The new species comes closer to C. (C.) tabonus, however it can be distinguished from the latter in having frons with irregular sculpture medially (smooth in C. (C.) tabonus), fore and mid tarsi brownish black (yellowish red in C. (C.) tabonus), hind tibia without white ring apically (with white ring in C. (C.) tabonus), hind tibia 4.0 × as long as wide (4.3 × in C. (C.) tabonus)