Carinostigmus nepalensis Tessy, Sureshan & Girish Kumar, 2020

Rajan, Tessy, Sureshan, P. M. & Kumar, P. Girish, 2020, Additions to the knowledge on the genus Carinostigmus Tsuneki (Hymenoptera Crabronidae: Pemphredoninae) from the Indian subcontinent with the description of two new species, Zootaxa 4881 (1), pp. 152-164 : 156-158

Carinostigmus nepalensis Tessy, Sureshan & Girish Kumar , sp. nov.

( Figs 11–20 )

Diagnosis. This new species can be separated from all other Carinostigmus species from the Indian subcontinent by the following character combinations: propodeal enclosure except basal section with irregular oblique transverse striations and smooth area posteriorly; mandible with no ivory markings; clypeus with median lobe not so convex, broader at apex, apex of clypeus almost rounded, not emarginated; ocular groove moderately broad along vertical section of inner eye margin and crenulations evanescent; underside of head moderately punctate especially towards middle and usually with few parallel carinae laterally; trochanters testaceous to yellow.

Carinostigmus nepalensis distinctly differs from Carinostigmus costatus Krombein in having the following characters: 1) propodeal enclosure except basal section with irregular oblique transverse striations and smooth area posteriorly (in C. costatus propodeal enclosure with radiating rugae on basal section, elsewhere rugose-reticulate); 2) mandible with no ivory markings (in C. costatus mandible with narrow ivory streak near base); 3) clypeus with median lobe not so convex, broader at apex, apex of clypeus almost rounded, not emarginated (in C. costatus clypeus with median lobe narrow, strongly produced, apex slightly emarginated); 4) ocular groove moderately broad along vertical section of inner eye margin and crenulations evanescent (in C. costatus ocular groove crenulate and moderately broad along vertical section of inner eye margin; 5) underside of head moderately punctate especially towards middle and usually with few parallel carinae laterally (in C. costatus underside of head with strong longitudinal costae except median area with delicate longitudinal lineolations narrowly; and 6) trochanters testaceous to yellow (in C. costatus trochanters black).

This new species distinctly differs from the Indian species Carinostigmus aterrimus Turner in having the following characters: 1) clypeus with median lobe not so convex, broader at apex, apex of clypeus almost rounded, not emarginated (in C. aterrimus clypeus with median lobe narrow, strongly produced, apex slightly emarginate); 2) ocular groove crenulations evanescent (in C. aterrimus , ocular groove crenulated distinctly; 3) notauli absent (in C. aterrimus notauli strongly impressed, crenulate); 4) scutellum discally with no scattered punctures (in C. aterrimus scutellum discally with few scattered punctures; 5)metanotum with coarse oblique striations (in C. aterrimus metanotum delicately shagreened in middle, obliquely rugulose laterally; and 6) propodeal enclosure except basal section with irregular oblique transverse striations and smooth area posteriorly (in C. aterrimus propodeal enclosure with radiating rugae on basal section, elsewhere rugose-reticulate; lateral surface obliquely rugose).

Description: Holotype ♀ ( Fig. 11 ). Head. Head in dorsal view moderately narrowed behind eyes ( Fig. 15 ); mandibles tridentate ( Fig. 14 ); clypeal median lobe not soweakly convex, broader at apex, apical margin almost rounded, not emarginated; interantennal projection strong, narrow erect and T- shaped ( Fig. 12 ); ocular groove moderately broad along vertical section of inner eye margin and crenulations evanescent ( Fig. 13 ); fronto-vertex shagreened; upper frons and vertex with sparse, tiny punctures, no groove before anterior ocellus; occipital groove narrow, weakly crenulate; underside of head moderately densely punctate especially towards middle and few parallel carinae laterally.

Mesosoma . Anterior pronotal ridge strong, narrowly emarginate in the middle, lateral angles spicate ( Fig. 15 ); notauli absent, parapsidal lines weakly impressed; scattered punctures on scutum, strong parallel ridges posteriorly, longer in middle than laterally; strongly depressed crenulate groove anteriorly on scutellum, no scattered puncturesdiscally; coarse oblique striations on metanotum; fore wing as in figure 17; irregular oblique transverse striations present on propodeal enclosure except basal section and smooth area posteriorly( Fig. 18 ).

Metasoma.Petiole slender, 6.4× as long as median width, acarinate laterally ( Fig. 19 ); pygidium depressed, shiny and ellipsoidal ( Fig. 20 ).

Colouration. Body black, shiny with metasoma dark brown. The following are testaceous to yellow: mandible except tip, underside of scape, underside of pedicel and first three flagellar segments, fore tibia, mid tibia, trochanters and all tarsi; pronotal lobe white. Wings clear, stigma and veins dark brown.

Size (measured from head to second tergite). 3.71 mm.

♂. Unknown.

Material examined: Holotype ♀, Nepal: Bagmati Pradesh, Kathmandu district, Kirtipur (27°39’46.8’’N, 85°16’38.64’’E), 2.ix.1972, Coll. M.S. Mani & Party, ZSIK Regd. No. ZSI/WGRC/IR/INV/12503.

Distribution: Nepal.

Etymology: The species is named after Nepal, the country from which holotype was collected.

Figures

FIGURES 11–20. Carinostigmus nepalensis Tessy, Sureshan & Girish Kumar, sp. nov., Holotype ♀. 11. Habitus, lateral view; 12. Head, frontal view; 13. Lower half of head, frontal view; 14. Mandible; 15. Head and mesosoma, dorsal view; 16. Mesosoma, lateral view; 17. Fore wing; 18. Propodeum; 19. Petiole and first tergite; 20. Metasoma, dorsal view.