Rhopalum (Corynopus) chettalicum Saini & Dey, 2024

Saini, Varun & Dey, Debjani, 2024, First record of subgenus Corynopus Lepeletier and Brullé, 1835 (Genus Rhopalum Stephens, Hymenoptera: Crabronidae: Crabronini) from India: a new species and a key to Asian species of the subgenus, Zootaxa 5507 (3), pp. 467-477 : 469-474

Rhopalum (Corynopus) chettalicum Saini & Dey , sp. nov.

( Figs 1–15 )

Diagnosis. The new species is close to R. gracile Wesmael, 1852 , sharing with it the following characters: mandible ferruginous; posterior lateral corner of propleuron without small tooth; hind tibiae black with yellow ring basally and markedly clavate & spinose; posterior surface of propodeum carinate; tergum I longer than hind femur; pygidium triangular and surrounded by carina. The new species differs from R. gracile and other species of the subgenus Corynopus by a slight clypeal emargination of medial lobe, orbital foveae distinct, fine longitudinal furrow between posterior ocelli present, pygidial plate with prominent medio-basal hump, coloration and punctuation on body and legs as described below.

Description. Head. Densely micro-sculptured dorsally but impunctate; clypeus medial emargination shallow; orbital fovea distinct, elliptical, basally joining compound eye; fine longitudinal line between posterior ocelli present ( Fig. 4 ). Mesosoma . Scutum and scutellum punctate; mesopleuron and lateral surface of propodeum micro-sculptured dorsally ( Fig. 10 ). Metasoma. Gt 1 longer than hind femur, straight, bend basally, nodose apically ( Fig. 12 ); pygidial plate with distinct medio-basal hump ( Figs 14–15 ).

FEMALE. Holotype ♀. BL= 6.9 mm; FWL= 4.56 mm; PPL= 0.49 mm.

Colour pattern and pubescence. Body black, except the following yellow: scape and pedicel (except dorsal spot), flagellum ventrally, pronotal lobe, maxillary & labial palpi, fore femur with large apical spot, fore tibia except small dorsal spot, fore and mid basitarsi completely, fore and mid tarsomeres except apically, mid tibia except large dorsal spot, hind femur with small apical spot and hind tibia basally ( Figs 1–2 ); apical portion of all coxae and pygidial plate apically yellowish-brown; mandible except apically, petiole, basal portion of Gt 2 to Gt 5 dorsally and sterna reddish brown; wing veins and flagellum light to dark brown. Body mostly with creamish-white setae; clypeus and scapal basin covered with dense silvery setae; upper frons and vertex with small, sparse, silvery setae; lateral surface of head covered with dense creamish-white setae; scutum covered with fine silvery setae; mesopleuron and lateral side of propodeum covered with dense creamish-white setae; Gt 2 to Gt 5 covered with small creamish-white setae ( Figs 12–13 ); pygidial plate laterally covered with elongate sparse brownish setae.

Head. Cubical, shiny, distinctly micro-sculptured dorsally, microsculpture dense near ocelli and vertex, length 0.7× of width; ocelli slightly broader than high ( Fig. 4 ); distance between compound eyes and antennal toruli very small, almost nil; inner margins of compound eyes convergent below, with carina; supra-antennal projection inconspicuous, covered with silvery setae; scapal basin shiny and slightly concave, inner orbit of compound eyes near scapal basin with silvery pubescence ( Fig. 3 ); indistinct longitudinal furrow extending from anterior ocellus to frontoclypeal groove; face narrow; clypeus broad, slightly swollen, anterior margin emarginate, with blunt projection on each side ( Figs 3, 6 ); vertex with fine longitudinal furrow starting from anterior ocellus and not reaching occipital carina; hypostomal carina wide U-shaped, separated from occipital carina ( Fig. 8 ); mandibles bifid at apex; antennal sockets contiguous; POD equal to 0.77 × of OOD; relative lengths of antennomeres I: II: III: IV: V: VI: VII: VIII: IX: X: XI and XII = 4.3: 1.1: 0.9: 0.9: 0.9: 0.8: 0.8: 0.9: 0.7: 0.7: 0.8 and 1.4 ( Fig. 7 ).

Mesosoma . Dull compared to head; dorsally covered with fine creamish-white setae; pronotal collar laterally dentate, slightly notched medially; prosternum with slight indentation ( Figs 5, 8 ); scutum densely micro-punctured, with well-defined admedian and parapsidal lines; scutellum broad and metanotum micro-punctate dorsally ( Fig. 9 ); mesopleuron shiny, micro-sculptured dorsally; epicnemial sulcus with distinct large foveolae, reaching tegula; precoxal area with small foveolae compared to those on epicnemial sulcus; mesopleural suture without fovea; metapleuron shiny, micro-sculptured dorsally ( Fig. 10 ); propodeum smooth, shiny, micro-sculptured dorsally, its anterior margin with fine foveolae, longitudinal furrow conspicuous and narrow, posterior surface dorsally micro-sculptured, lateral surface with fine transverse striae ( Fig. 11 ); fore tibia without dorsal spines, mid tibia simple, with 2-4 spines dorsally, hind tibia largely inflated apically with 8-10 short spines dorsally, ventrally with dense silvery pubescence.

Wings. Recurrent vein joining sub marginal cell slightly beyond its middle.

Metasoma. Petiolate, petiole longer than combined length of hind trochanter and hind femur, distinctly nodose at apex; Gt 2 longer than wide, Gt 1 to Gt 5 covered with short pubescence dorsally ( Figs 12–13 ); pygidial plate triangular, broader at base, with medio-basal gibbosity, depressed and rounded apically, carinate laterally, ferruginous with thick brown bristles ( Figs 14–15 ).

MALE. Unknown.

Etymology. The species name is based on the type locality ( Fig. 16 ).

Material examined. Holotype ♀, India: Karnataka, Coorg (= Kodagu), Chettali , 10.vi.2012, coll. Roni (NPC-IARI).

Figures

FIGURE 16. Collecting locality of Rhopalum (Corynopus) chettalicum sp. nov. Holotype ♀.

FIGURES 1–2. Rhopalum (Corynopus) chettalicum sp. nov. Holotype ♀. 1. Habitus, lateral view; 2. Habitus, ventral view.

FIGURES 3–8. Rhopalum (Corynopus) chettalicum sp. nov. Holotype ♀. 3. Head, frontal view; 4. Head, dorsal view; 5. Head, lateral view; 6. Clypeus; 7. Antenna; 8. Head, ventral view.

FIGURES 9–11. Rhopalum (Corynopus) chettalicum sp. nov. Holotype ♀. 9. Mesosoma, dorsal view; 10. Mesosoma, lateral view; 11. Propodeum.

FIGURES 12–15. Rhopalum (Corynopus) chettalicum sp. nov. Holotype ♀. 12. Metasoma, lateral view; 13. Tergum I; 14–15. Pygidial plate, dorsal & lateral view.