Xanthopygus Kraatz 1857
Creators: name: Chatzimanolis, Stylianos
Publisher: name: Zenodo
Year: 2022
Subjects: Biodiversity
Taxonomy
Animalia
Arthropoda
Insecta
Coleoptera
Staphylinidae
Xanthopygus

description: Key to the species of Xanthopygus
1. Antennomere 4 without tomentose pubescence (Figs. 18, 39); mandibles more or less straight except tip (Figs. 15, 37); eyes as long as 1/4 length of head (Figs. 15, 37); head appearing flat (Figs. 15, 37); sternite 6 with two anterior transverse lines (Fig. 17)................................................................................................ 2
- Antennomere 4 with tomentose pubescence (Figs. 10, 26, 33, 43, 50); mandibles curved from apical half (Figs. 1 – 2, 7, 40, 47); eyes as long as 1/3-2/5 length of head (Figs. 7, 23, 30, 40, 47); head appearing convex (Figs. 7, 23, 30, 40, 47); sternite 6 with single anterior transverse line (Fig. 9)..................................................................... 3
2. Antennomere 3 clearly longer than 2 (Fig. 18); pronotum microsculpture polygon shaped; tergite 6 sparsely punctate; tip of paramere emarginate (Figs. 19, 21).............................................................. X. luctuosus
- Antennomere 3 subequal to 2 (Fig. 39); pronotum microsculpture with transverse lines; tergite 6 densely punctate; no male specimens known............................................................................ X. oliveirae
3. Antennomere 4 longer than wide (Fig 50); pronotum densely punctate, typically with three rows of punctures on each half beside median line (Fig. 48); sternite 7 in males with porose structure (Fig. 49)........................ X. xanthopygus
- Antennomere 4 subquadrate (Figs. 10, 26, 33, 43); pronotum not densely punctate, typically with two or less rows of punctures on each half beside median line (Figs. 8, 24, 31, 41); sternite 7 in males without porose structure (Figs. 9, 25, 32, 42)..... 4
4. Head and pronotum with medium to large size punctures (Figs. 7–8, 40–41); pronotum with 1–2 dense rows of punctures on each half beside median line (Figs. 8, 41); abdominal segments 4–6 with iridescent overtones under strong light (Figs. 7, 40). ................................................................................................... 5
- Head and pronotum with small to medium size punctures (Figs. 23–24, 30–31); pronotum with one sparse row of punctures on each half beside median line (Figs. 24, 31); abdominal segments 4–6 not iridescent under strong light (Figs. 23, 30........ 6
5. Abdominal segment 7 completely orange (Figs. 7, 9); abdominal segment 6 with a distinct bright band of orange coloration posteriorly (Figs. 7, 9); aedeagus with median lobe lacking subapical tooth (Fig. 12); paramere in lateral view much shorter than median lobe (Figs. 11–12)..................................................................... X. cognatus
- Abdominal segment 7 never completely orange, typically anterior half dark or light brown (Figs. 40, 42); abdominal segment 6 without a distinct bright band of orange coloration posteriorly (Figs. 40, 42); aedeagus with median lobe having a subapical tooth (Fig. 45); paramere in lateral view slightly shorter than median lobe (Figs. 44–45)....................... X. pexus
6. Paramere apically emarginate (Figs. 34, 36); known from Peru ............................................ X. max
- Paramere apically rounded (Figs. 27, 29); known from Colombia ......................................... X. major
description: Published as part of Chatzimanolis, Stylianos, 2022, A revision of the genus Xanthopygus Kraatz (Staphylinidae: Xanthopygina), pp. 151-178 in Zootaxa 5099 (2) on page 176, DOI: 10.11646/zootaxa.5099.2.1, http://zenodo.org/record/6048483