Chelonus (Megachelonus) novis sp. nov.

(Figures 10–13)

urn:lsid:zoobank.org:act: 63887CE3-DB17-4263-A253-BFC988C8227C

Material examined. Holotype, female, INDIA: Nagaland, Jotsoma, Kohima Science College Campus, 25°39’56 N, 94°04’31 E, 1671 m.a.s.l., 12.iii.2021, coll. Ranjith, A.P. Paratypes 1 female and 2 males with same data as holotype (AIMB) .

Description. Holotype, female, length of body 4.5 mm, of fore wing 3.5 mm.

Head. Antenna with 16 antennomeres, apical antennomeres not broadened, shorter than basal antennomeres (Fig. 10A); third antennomere as longer than fourth; third, fourth and terminal antennomeres 4.6 ×, 4.2 × and 1.9 × longer than wide, respectively; head transverse (Fig. 10B), in dorsal view roundly contracted behind eyes (Fig. 9E); OOL: OD: POL= 2.5: 1.0: 1.7; longitudinal diameter of eye 1.8 × height of temples; vertex coarsely striate-rugose (Fig. 10E); frons distinctly concave, striate-rugose medially with a complete midlongitudinal carina, longitudinally striate laterally (Figs 10C, E); occiput transversely striate-rugose (Fig. 9E); temple longitudinally striate-rugose (Fig. 10F); face coarsely reticulate-rugose laterally, transversely striate-rugose anteriorly, densely setose in lateral view (Fig. 10B); clypeus flat and densely punctate, smooth and shining (Fig. 10B); length of malar space 2.3 × basal width of mandible.

Mesosoma. Length of mesosoma 1.4 × its height; pronotum rugose laterally (Fig. 11A); mesoscutum areolate-rugose, with longitudinal depressions medially (Fig. 11B); lateral lobe of mesoscutum rugose (Fig. 11B); notauli impressed as large pits (Fig. 11B); transverse suture distinct, deep (Fig. 11B); scutellar sulcus divided by six carinae (Fig. 11B); scutellum punctate medially, sparsely setose, with crenulate groove laterally (Fig. 11B); mesopleuron evenly convex, coarsely reticulate-rugose, setose (Fig. 11A); metanotum crenulate with distinct midlongitudinal carina (Figs 11C–D); propodeum without tubercles, coarsely reticulate-rugose, with triangular areola delineated by carina, transverse carina indistinct, but complete (Figs 10C–D).

Wings. Fore wing infuscate subbasally and subapically (Figs 13A–B); length of fore wing 2.8 × its width; length of marginal cell 1.4 × pterostigma; vein 2-Rl present (Fig. 13A); vein r as long as 3-SR (Fig. 13A); r: 3-SR: SRl = 1.0: 1.0: 4.6; SRl straight; parastigma distinctly swollen (Fig. 13A); 1-CU1: 2-CU1= 1.0: 2.6; vein CUlb present (Fig. 13A).

Legs. Hind coxa smooth, densely short setose (Fig. 11E); hind femur robust (Figs 11E, 12C); length of hind femur, tibia and basitarsus 3.1 ×, 4.8 × and 3.8 × their maximum width, respectively; mid and hind tibia with numerous short, pointed spines apical half (Figs 12B–C).

Metasoma. Metasomal carapace elongate-oval in dorsal view, coarsely reticulate-rugose, with a pair of posteriorly converging midlongitudinal carinae basally (Figs 11F, 13B); length of carapace 2.2 × its maximum width in dorsal view; carapace without undulating lamella laterally (Fig. 11E); ventral cavity closed apically (Fig. 12B), with a pair of short and blunt teeth (Fig. 12A); ovipositor long, slender (Fig. 11E) and the ovipositor sheath 0.08 × as long as fore wing, 0.3 × as long as hind tibia.

Colour. Black except eyes grey, maxillary and labial palps, fore coxa, trochanter, mid coxa, trochanter, mid femur basally, hind coxa apically, hind trochanter, mid and hind tibia subbasally, fore wing basally, metasomal carapace basolaterally, mid and hind tibial spurs yellow, fore femur, fore tibia, hind trochantellus apically reddish brown.

Male. Similar to female except antenna with 23 antennomeres, scutellar sulcus divided by five carinae (Fig. 13B).

Biology. Unknown.

Distribution. India (Nagaland).

Etymology. The species name ‘ novis ’ (Latin for strange) is pointing the presence of several new characters which are not yet recorded in the subgenus Megachelonus .

Comparative diagnosis. The new species exhibit some strikingly new apomorphic characters such as apical antennomeres not broadened, propodeum without lateral tubercles and propodeum with a triangular areola mediobasally which are not yet recorded from the subgenus Megachelonus . Within the subgenus the new species belongs to the group of species having 16 antennomeres. In that group the new species is comes close to C. (M.) irilaminatus in having metasomal carapace without undulating lamellae laterally and carapace with a pair of short teeth medio-apically. Apart from the differences cited in the key, the new species distinctly differs from C. (M.) irilaminatus in having the following characters; mid and hind femur black (yellow in C. (M.) irilaminatus), OOL 1.4 × as long as POL (1.1 × in C. (M.) irilaminatus), scutellar sulcus divided by 6 carinae (4 in C. (M.) irilaminatus), scape brownish black (yellowish brown in C. (M.) irilaminatus).