Diochus, Erichson, 1839

Huang, Tian, Zhou, Yu-Lingzi, Janák, Jiří & Zhou, Hong-Zhang, 2024, Four new species and a key to Australian species of the genus Diochus Erichson (Coleoptera: Staphylinidae, Staphylininae, Diochini), Zootaxa 5512 (3), pp. 343-372 : 345-346

Key to species of Australian Diochus

1 Antennomeres 4−10 uniformly colored.................................................................... 2

- Antennomeres 4−10 not uniformly colored, gradually lightened toward apex...................................... 4

2 Antennae long, if flexed backward, reaching posterior margin of pronotum; antennomere 4 distinctly elongate, about 3 times longer than wide; body paler, with pronotum and elytra yellowish brown; body large, with length 5.2−6.3 mm ................................................................................... ( Fig 2-1A ) Diochus basseti sp. nov.

- Antennae shorter, backward reaching about pronotum half; antennomere 4 slightly elongate, about 2 times longer than wide or less; body more darkly colored, with pronotum and elytra reddish brown to black brown; body smaller, with length: 3.8−4.4 mm ................................................................................................ 3

3 Antennomeres 4−10 transverse, distinctly widened toward apex................................ ( Fig 7 ) D. longus Lea

- Antennomeres 4−10 not transverse, slightly widened toward apex...................... (Fig 5-1A) D. slipinskii sp. nov.

4 Elytra not uniformly colored, at least apical margin pale....................................................... 5

- Elytra uniformly colored, dark brown to black brown......................................................... 6

5 Elytra with half or more pale....................................................... (Fig 6-1) D. divisus Fauvel

- Elytra with apical margin pale......................................................(Fig 9-1) D. pubiventri s Lea

6 Posterior margin of male sternite VIII with wide and shallow emargination in middle, without any thick and short setae.... 7

- Posterior margin of male sternite VIII without wide and shallow emargination in middle, but nearly straight, with a row of thick and short setae ( Fig 8E )............................................................ ( Fig 8A ) D. octavii Fauvel

7 Posterior margin of male sternite VIII with only one emargination in middle, rounded at both sides (Fig 3-1E)...........................................................................................(Fig 3-1A) D. weiri sp. nov.

- Posterior margin of male sternite VIII with an emargination in middle, each side with shallower emargination, acute on both sides (Fig 4-1E)............................................................. (Fig 4-1A) D. lawrencei sp. nov.

Figures

FIGURE 7. Diochus longus Lea, 1929, holotype:A. habitus, dorsal view; B. habitus, lateral view; C. labels. (Scale bars: 0.5 mm).

FIGURE 8. Diochus octavii Fauvel, 1877, holotype:A. habitus, dorsal view; B. forebody, dorsal view; C. antenna; D. aedeagus, dorsal view; E. male sternite VIII; F. male tergites IX–X; G. male tergite VIII; H. male sternite IX; I. labels. (Scale bars: A–B = 0.5 mm, D–E = 0.1 mm).

FIGURE 2-2. Diochus basseti sp. nov.: A. aedeagus, dorsal view; B. male sternite VIII; C. male tergite VIII; D. male tergites IX–X; E. male sternite IX; F. female sternite VIII; G. female sternite X; H. female sternite IX; I. spermatheca. (Scale bars: 0.1 mm).