Diochus

Huang, Tian, Janák, Jiří & Zhou, Hong-Zhang, 2024, Taxonomy of the genus Diochus Erichson (Coleoptera: Staphylinidae, Staphylininae, Diochini) of Papua New Guinea, Vanuatu and Solomon Islands, Zootaxa 5519 (1), pp. 103-118 : 104

Key to species of the genus Diochus from Papua New Guinea, Vanuatu and Solomon Islands ( Figs 1−5 )

1 Elytra extremely short, one sixth shorter than pronotum ( Fig 5 )........................... D. papuanus Cameron, 1939

- Elytra of normal length, about as long as pronotum.......................................................... 2

2 Antennomeres very long; antennomere 3 distinctly elongate, about 5 times longer than wide; body length 5.5−6.1 mm ( Fig 2 )................................................................................... D. elongatus sp. nov.

- Antennomeres shorter; antennomere 3 slightly elongate, about 2 to 4 times longer than wide; body length less than 5 mm .. 3

3 Antennomere 3 more elongate, distinctly longer than antennomere 2; head narrower at posterior angle; tube of spermatheca shorter, slightly coiled (Fig 3)............................................................... D. loebli , sp. nov.

- Antennomere 3 less elongate, nearly equal to antennomere 2; head wider at posterior angle; tube of spermatheca longer, strongly coiled (Fig 4)................................................................ D. chambrieri sp. nov.

Figures

FIGURE 1. Habitus of four species from Papua New Guinea, Vanuatu and Solomon Islands in dorsal view:A. Diochus elongatus sp. nov.; B. D. chambrieri sp. nov.; C. D. papuanus Cameron, 1939, D. D. loebli sp. nov. (Scale bar: 0.5 mm).

FIGURE 2-2. Diochus elongatus 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: A = 0.05 mm, B–I = 0.1 mm).

FIGURE 5. Diochus papuanus Cameron, 1939:A. forebody, dorsal view; B. antenna; C. male sternite VIII; D. male tergite VIII; E. male sternite IX; F. male tergites IX–X; G. aedeagus, dorsal view; H. labels. (Scale bars: A = 0.5 mm, B–G = 0.1 mm).