Description of Rhopalum (s. str.) gulmargense n. sp. with a key to the Indian species of the subgenus Rhopalum Stephens, 1829 s. str. (Hymenoptera: Crabronidae: Crabronini) Author Saini, Varun 0000-0003-4859-869X National Pusa Collection, Division of Entomology, ICAR-Indian Agricultural Research Institute, New Delhi- 110012, Delhi, India & varuninsectaxonomist @ gmail. com; https: // orcid. org / 0000 - 0003 - 4859 - 869 X varuninsectaxonomist@gmail.com Author Dey, Debjani National Pusa Collection, Division of Entomology, ICAR-Indian Agricultural Research Institute, New Delhi- 110012, Delhi, India text Zootaxa 2022 2022-03-02 5105 1 139 144 journal article 20363 10.11646/zootaxa.5105.1.6 bb6734ad-fde7-4daf-bd8c-4da4d7c0c868 1175-5326 6332496 C3BA147D-BBA0-47DF-8360-3DD537BD8C2B Key to the species of subgenus Rhopalum s. str. Stephens from Indian subcontinent (Males of R. peterseni Tsuneki and R. gulmargense sp. nov . are unknown) 1. Female............................................................................................. 2 - Male............................................................................................... 6 2. Inter-antennal projection indistinct........................................................................ 3 - Inter-antennal projection conspicuous, prominent........................................................... 4 3. Clypeus: medial lobe truncate apically with inconspicuous lateral indentation; antennomere III not longer than wide; admedian line on scutum inconspicuous, mesopleuron smooth; hindtibia inconspicuously swollen apically.. R. croisseti Leclercq, 2011 - Clypeus: anterior margin rounded and slightly notched or broad with conspicuous lateral indentation ( Fig. 4 ); antennomere III as long as or longer than wide; admedian line on scutum distinct; mesopleuron at least with distinct micro punctures; hindtibia different............................................................................................ 5 4. Clypeus: anterior margin minimally indented; inter-antennal tooth more or less truncate, directed downwards; punctation on mesoscutum very fine but clear and relatively dense; narrow yellow stripe on posterior surface of hindtibia, starting from base, not reaching apex; petiole moderately nodose apically.................................... R. avexum Leclercq, 1963 - Clypeus: anterior margin truncate (Fig. 181 of Tsuneki 1976 ); inter-antennal tooth rounded apically, directed forward (Fig. 182 of Tsuneki 1976 ); punctation on mesoscutum large; basal ring of hindtibia broad; petiole largely nodose apically (Fig. 184 of Tsuneki 1976 )................................................................... R. peterseni Tsuneki, 1976 5. Body length: 6.4 mm ; face narrow; anterior margin of clypeus rounded, slightly notched with inconspicuous lateral indentation; inner margin of compound eyes without carina; orbital fovea absent; hindtibia 3 inconspicuously swollen apically; pygidial area narrow at base..................................................................... R. adamsi Leclercq, 2011 - Body length: 7.4−7.6 mm ; face broad; clypeus broad, slightly swollen medially, anterior margin dentate with conspicuous lateral indentation ( Fig. 4 ); inner margin of compound eyes with well-defined carina ( Fig. 4 ); orbital fovea indistinct but not absent, elliptical ( Fig. 3 ); hindtibia markedly swollen apically ( Fig. 2 ); pygidial area broader at base ( Fig. 8 )................................................................................... R. gulmargense Saini & Dey , sp. nov. 6. Antennomere VI or VII indented; clypeus free margin not tridentate; pygidial area without lateral border or with well-defined border.............................................................................................. 7 - Antennomere VI and VII not indented; clypeus free margin tridentate; pygidial area bordered laterally but not apically; length 4.2 mm ......................................................................... R. croisseti Leclercq, 2011 7. Clypeus: medial lobe subtruncate; tergum VII without border laterally; length 6 mm ............. R. adamsi Leclercq, 2011 - Clypeus: median lobe rounded apically; tergum VII forming flat pygidial area, with well-defined border; length 6.5 mm ................................................................................... R. avexum Leclercq, 1963