Amphichroum Kraatz 1857
Creators: name: Shavrin, Alexey V.
name: Smetana, Aleš
Publisher: name: Zenodo
Year: 2018
Subjects: Biodiversity
Taxonomy
Animalia
Arthropoda
Insecta
Coleoptera
Staphylinidae
Amphichroum

description: Key to species of Amphichroum of China
1 Basal portion of internal sac with paired, very large sclerotized structures......................................... 2
- Basal portion of internal sac with significantly smaller sclerotized structures or without them......................... 4
2 Pronotum with distinct longitudinal reddish-brown spot. Median lobe (Fig. 14) markedly, evenly narrowed toward acute apex; internal sac with two very long apical thorns (Fig. 15). Body length:2.00–2.35. Habitus as in Fig. 4. Yunnan ................................................................................................... A. maculosum sp.n.
- Pronotum without spot. Shape of median lobe and internal sac different........................................... 3
3 Elytra longer than wide. Forebody yellow to yellow-brown, abdomen reddish-brown. Parameres slightly exceeding apex of median lobe; sclerotized structures in basal part of internal sac very large and wide (Fig. 12). Body length:2.10–3.65. Habitus as in Fig. 3. Sichuan .................................................................. A. longilobatum sp.n.
- Elytra distinctly wider than long. Body yellow-brown to reddish-brown. Parameres distinctly exceeding apex of median lobe; sclerotized structures in basal part of internal sac smaller and narrower (Fig. 20). Body length:3.00–3.15. Habitus as in Fig. 16. Sichuan ............................................................................. A. propinquum sp.n.
4 Apical portion of internal sac with wide thorns.............................................................. 5
- Apical portion of internal sac without wide thorns............................................................ 6
5 Aedeagus moderately wide, with short parameres (Fig. 5); internal sac with two pairs of wide thorns in apical and complicated sclerotized structures in basal portion (Fig. 5). Body length:2.85–3.10. Habitus as in Fig. 1. Yunnan .. A. angustilobatum sp.n.
- Aedeagus narrow, with longer narrow parameres (Fig. 24); internal sac with several wide thorns in apical and sclerotized ringlike structure in basal portion (Fig. 25). Body length:2.20–3.75. Habitus as in Fig. 18. Yunnan ............ A. schuelkei sp.n.
6 Median lobe with rounded apex.......................................................................... 7
- Median lobe with subacute or narrowly arcuate apex.......................................................... 8
7 Parameres considerably exceeding apex of median lobe, basal portion of internal sac without oval structure (Fig. 22–23). Head, pronotum and abdomen reddish-brown, elytra yellow-brown to brown. Body length: 2.81–3.75 mm. Habitus as in Fig. 17. Sichuan ........................................................................... A. rotundatum sp.n.
- Parameres moderately exceeding apex of median lobe, basal portion of internal sac with oval structure (Fig. 39–40). Forebody yellow-brown, abdomen reddish-brown. Body length:3.20–3.85. Habitus as in Fig. 34. Tibet ............ A. tibetanum sp.n.
8 Anterior angles of pronotum distinctly protruded anteriad. Median lobe with subacute apex; internal sac with ring-like structure in basal part (Figs. 8–9). Body length:3.55–4.95. Habitus as in Fig. 2. Yunnan ...................... A. assingi sp.n.
- Anterior angles of pronotum not protruded anteriad. Median lobe with narrowly arcuate apex; internal sac without ring-like structure in basal part.................................................................................. 9
9 Median lobe narrow; parameres short, reaching apex of median lobe (see Watanabe 1999: Fig. 2). Body length: 2.80–3.20 mm. Habitus (see Watanabe 1999: Fig. 1). Guangxi .................................... A. miaoershanum Watanabe, 1999
- Median lobe wider; parameres longer, distinctly exceeding apex of median lobe................................... 10
10 Apical portion of median lobe wide; parameres relatively wide (Fig. 37). Body length:3.50–4.80. Habitus as in Fig. 33. Sichuan ............................................................................... A. subelongatum sp.n.
- Apical portion of median lobe narrow; parameres narrow..................................................... 11
11 Elytra slightly wider than long. Aedeagus narrow; basal portion of internal sac with wide field of large thorns (Fig. 35). Body length: 2.90–4.00 mm. Habitus as in Fig. 32. Shaanxi .......................................... A. subaequale sp.n.
- Elytra slightly longer than wide. Aedeagus wider basally; basal portion of internal sac with very wide, strongly sclerotized thorns (Fig. 27).Body length:2.90–3.95. Habitus as in Fig. 19. Sichuan ............................ A. squamosum sp.n.
description: Published as part of Shavrin, Alexey V. & Smetana, Aleš, 2018, New species of the genus Amphichroum Kraatz, 1857 (Coleoptera: Staphylinidae: Omaliinae: Anthophagini) from China, pp. 377-402 in Zootaxa 4508 (3) on pages 401-402, DOI: 10.11646/zootaxa.4508.3.3, http://zenodo.org/record/2607216