Rhytomus
Creators: name: Génier, François
name: Gunter, Nicole L.
name: Saxton, Natalie A.
Publisher: name: Zenodo
Year: 2025
Subjects: Biodiversity
Taxonomy
Animalia
Arthropoda
Insecta
Coleoptera
Scarabaeidae
Rhytomus

description: Key to adult mainland New Guinea Rhytomus species
Access to online key: https://keys.lucidcentral.org/keys/v4/rhytomus/ (click on the magic wand icon to select the best character to use first)
1 Interstriae 3–5 on basal fifth all having unaligned scattered punctures (Fig. 11A); basal pseudepipleural pit present, shallow and slightly larger than stria 10 (Fig. 11D).................................................................... 2
- Interstriae 3–5 with at least one interval having two distinct rows of punctures on basal fifth (11B); basal pseudepipleural pit deep and distinctly larger than stria 10 (Fig. 11C) OR pseudepipleural pit is absent................................. 5
2 Elytral interval 1 with basal punctures much smaller in size to those in intervals 2–3; pronotal lateral edge obsolete or sharply defined............................................................................................. 3
- Elytral interval 1 with basal punctures similar in size and coarseness to those in intervals 2–3; pronotal lateral edge always sharply defined...................................................................................... 4
3 Pronotal lateral edge obsolete; male clypeal edge without emargination lateral to clypeal teeth (Fig. 4B); Body length 4–5.3 mm .................................................................... Rhytomus papuanus (Paulian, 1985)
- Pronotal lateral edge sharply defined; male clypeal edge with emargination lateral to clypeal teeth (Fig. 4A); Body length 3.6–4.1 mm .............................................................. Rhytomus howdeni (Paulian, 1985)
4 Basal pseudepipleural surface with irregularly distributed more or less defined punctures (Fig. 11E); female pygidium depressed apically...................................................... Rhytomus fervidus Saxton & Génier, new species
- Basal pseudepipleural surface with sharply defined ocellate punctures (Fig. 11F); female pygidium evenly convex.................................................................................. Rhytomus heurni (Paulian, 1937)
5 Base of pronotum lacking fine longitudinal depression medially; basal pseudepipleural pit deep and distinctly larger than stria 10 (Fig. 11C); male pygidial groove not distinctly narrowed medially (Figs. 8D, H, I)............................... 6
- Base of pronotum with fine longitudinal depression medially (Fig. E); basal pseudepipleural pit absent; male pygidial groove distinctly narrowed medially and terminating in pits (Fig. 8E)........ Rhytomus latidentatus Saxton & Génier, new species
6 Interstriae 3, 4 and 5 having two distinct rows of punctures; elytral pubescence long and conspicuous (Fig. 11B)......... 7
- Interstriae 3 and 5 having unaligned and scattered punctures, interstriae 4 having two distinct rows of punctures; elytral pubescence short and fine (as in Fig. 11A)................................................................. 9
7 Male metatibial apicointernal tooth approximately in line with posterior tibial edge (Fig. 12C); pygidium of female depressed basally; body length 3.0– 4.6 mm .................................. Rhytomus sodalis Saxton & Génier, new species
- Male metatibial apicointernal tooth set anteriorly to posterior tibial edge (Fig. 12D); pygidium of female evenly convex: body length 4.1–6.0 mm.................................................................................... 8
8 Elytral surface between punctures dull, with distinct microsculptures (Fig. 7D, 11B); Body length 4.1–5.4 mm ......................................................................... Rhytomus larseni Saxton & Génier, new species
- Elytral surface between punctures appearing glossy, at most with ill-defined microsculptures (Fig. 6A); Body length 6mm ................................................................... Rhytomus elongatus (van Lansberge, 1885)
9 Elytral surface appearing glossy, at most with ill-defined microsculpture (as in Fig. 12B); Elytra strongly convex in lateral view (Fig. 12E).............................................................. Rhytomus setulosus (Balthasar, 1965)
- Elytral surface dull, with distinct microsculpture (Fig. 12A); Elytra moderately convex in lateral view (Fig. 12F)........................................................................ Rhytomus vanus Saxton & Génier, new species
description: Published as part of Génier, François, Gunter, Nicole L. & Saxton, Natalie A., 2025, Rhytomus Génier & Saxton: A new dung beetle genus from New Guinea with five new species and phylogenetic insights (Coleoptera: Scarabaeidae: Scarabaeinae), pp. 87-110 in Zootaxa 5575 (1) on page 107, DOI: 10.11646/zootaxa.5575.1.3, http://zenodo.org/record/14746442