Diochus Erichson 1839
Creators: name: Huang, Tian
name: Janák, Jiří
name: Zhou, Hong-Zhang
Publisher: name: Zenodo
Year: 2025
Subjects: Biodiversity
Taxonomy
Animalia
Arthropoda
Insecta
Coleoptera
Staphylinidae
Diochus

description: Key to species of the genus Diochus of Indonesia, Malaysia and Singapore
(Figs 1 −11)
1 Antennomeres longer: antennomere 3 more elongate, distinctly longer than antennomere 2; antennomere 4 more elongate, more than twice as long as wide.............................................................................. 2
- Antennomeres shorter: antennomere 3 less elongate, nearly equal to antennomere 2; antennomere 4 less elongate, less than twice as long as wide.................................................................................. 7
2 Tibiae partly in black color; known only from Borneo (Kalimantan, Indonesia)................................................................................................................. D. borneensis Cameron, 1933
- Tibiae not in black color................................................................................ 3
3 Body larger, longer than 6 mm; posterior margin of male sternite VIII emarginate medially, and with shallower emarginations on both sides......................................................................................... 4
- Body smaller, shorter than 5.5 mm; posterior margin of male sternite VIII only emarginate medially, or with deeper emarginations on both sides......................................................................................... 5
4 Posterior margin of male sternite VIII with medial emargination deep and rounded, posterior angles strongly sharpened..................................................................... D. paradoxus Huang, Janák & Zhou, sp. nov.
- Posterior margin of male sternite VIII with medial emargination shallow, not rounded, posterior angle slightly sharpened................................................................ D. paraparadoxus Huang, Janák & Zhou, sp. nov.
5 Posterior margin of male sternite VIII with medial emargination very deep, posterior angles strongly sharpened and projecting; known only from Borneo (Kalimantan, Indonesia)...................... D. parellipticus Huang, Janák & Zhou, sp. nov.
- Posterior margin of male sternite VIII with medial emargination shallow, not so rounded, with posterior angles not sharply projecting........................................................................................... 6
6 Head and pronotum more elongate; male sternite VIII distinctly narrowed at apex; aedeagus with parameres shorter and thicker........................................................ D. sulawesiensis Huang, Janák & Zhou, sp. nov.
- Head and pronotum less elongate; male sternite VIII not distinctly narrowed at apex; aedeagus with parameres longer and thinner................................................................. D. punctipennis (Motschulsky, 1858)
7 Elytra not in a uniform color, but in bicolor; basal transverse carina of male and female sternite VIII interrupted or absent................................................................................ D. pulchellus Cameron, 1918
- Elytra in a uniform color; basal transverse carina of male or female sternite VIII entire.............................. 8
8 Posterior margin of male sternite VIII nearly straight at middle, with slight emargination on both sides; basal margin of male sternite IX narrower than apical margin............................... D. lombokensis Huang, Janák & Zhou, sp. nov.
- Posterior margin of male sternite VIII emarginate at middle; basal margin of male sternite IX wider than apical margin..... 9
9 Posterior margin of male sternite VIII emarginate at middle and on both sides; aedeagus with parameres very short........................................................................ D. bogorensis Huang, Janák & Zhou, sp. nov.
- Posterior margin of male sternite VIII only emarginate at middle; aedeagus with parameres thin and long.............. 10
10 Pronotum more elongate; posterior margin of male sternite VIII with medial emargination deeper; basal transverse carina of male sternite VIII deeply produced at middle........................... D. uvellipticus Huang, Janák & Zhou, sp. nov.
- Pronotum not so elongate; posterior margin of male sternite VIII with medial emargination shallower; basal transverse carina of male sternite VIII shallowly produced at middle.......................................................... 11
11 Basal transverse carina of male sternite VIII sharp at middle; aedeagus with a T-shaped sclerite distally; body darker............................................................................... D. antennatus (Motschulsky, 1858)
- Basal transverse carina of male sternite VIII rounded at middle; aedeagus without T-shaped sclerite distally; body lighter.................................................................... D. acehensis Huang, Janák & Zhou, sp. nov.
description: Published as part of Huang, Tian, Janák, Jiří & Zhou, Hong-Zhang, 2025, Revision of the genus Diochus Erichson (Coleoptera: Staphylinidae, Staphylininae, Diochini) from Indonesia, Malaysia and Singapore, pp. 441-479 in Zootaxa 5632 (3) on pages 442-443, DOI: 10.11646/zootaxa.5632.3.2, http://zenodo.org/record/15372327