Systellopini, Von Dalla Torre, 1912

Hutchinson, Paul M. & Allsopp, Peter G., 2022, Liomenochilus ongi (Coleoptera: Scarabaeidae: Melolonthinae: Systellopini), a new genus and new species from northern Western Australia, Zootaxa 5100 (1), pp. 119-128 : 124

Key to genera of Systellopini (males only)

(modified from Allsopp 1990)

1 Antennal club with 3 long lamellae ( Figs. 1–2 ); labrum fused with clypeus dorsally (visible only at lateral declivity) ( Figs. 4–5 ); clypeus widest at base, non-emarginate before ocular canthus ( Figs. 4–5 )..................................................................................................... Liomenochilus Hutchinson & Allsopp , new genus

- Antennal club with 5, 6 or 7 long lamellae ( Figs. 19–24 ); labrum clearly separated from clypeus by a suture ( Figs. 19–24 ); clypeus constricted at base ( Figs. 19–24 )................................................................... 2

2 Lamellae of antennal club fringed with long, pilose filaments ( Figs. 18 , 22 ).............. Sarothromerus Blackburn, 1907

- Lamellae of antennal club setose or glabrous ( Figs. 19–21, 23–24 ).............................................. 3

3 Labrum short, length:width ratio <0.3:1 ( Figs. 17 , 24 ); metafemora strongly dilated, length:width ratio <1.3:1............................................................................................ Systellopus Sharp, 1877

- Labrum longer, length:width ratio> 0.3:1 ( Figs. 12–16 , 19–21, 23 ); metafemora less strongly dilated, length:width ratio> 1.4:1............................................................................................... 4

4 Antennal club with 5 lamellae, inner faces of lamellae glabrous................................................. 5

- Antennal club with 5, 6 or 7 lamellae, inner faces of lamellae setose............................................. 6

5 Canthus at level of middle of eye, frons narrow ( Figs. 12 , 19 ); dorsal labrum with transverse ridge dividing rugose anterior third from smooth posterior portion ( Fig. 19 ); posterior portion of epipleurae spinose ( Fig. 12 ); disc of pronotum glabrous ( Figs. 12 , 19 ).............................................................................. Chilodiplus Sharp, 1877

- Canthus well above level of middle of eye, frons wide ( Figs. 16 , 23 ); dorsal labrum with reflexed anterior and lateral margins forming a continuous ridge ( Fig. 23 ); posterior portion of epipleurae without spines ( Fig. 16 ); disc of pronotum setose ( Figs. 16 , 23 )........................................................................... Sphyrocallus Sharp, 1877

6 Disc of pronotum glabrous ( Figs. 14 , 21 ), antennal club with 5 or 6 lamellae................. Prochelyna Erichson, 1847

- Disc of pronotum at least with patch of setae in anterolateral angles, usually across entire pronotal disc but possibly effaced ( Figs. 13 , 20 ); antennal club with 5, 6 or 7 lamellae........................................ Enamillus Sharp, 1877

Figures

FIGURES 1–7. Liomenochilus ongi Hutchinson & Allsopp, new species, holotype male. 1, dorsal view; 2, ventral view; 3, lateral view; 4, head, dorsal view; 5, head and pronotum, oblique view; 6, pygidium; 7, label.

FIGURES 19–24. Representative males of each of six systellopine genera, head and pronotum, oblique view. 19 Chilodiplus weiri Allsopp, 1993 (photograph by CSIRO). 20, Enamillus pilicollis (Sharp, 1877). 21 Prochelyna heterodoxa Burmeister, 1855. 22, Sarothromerus sharpi (Blackburn, 1905). 23, Sphyrocallus brunneus Sharp, 1877. 24, Systellopus obtusus Sharp, 1877.

FIGURES 12–18. 12–17. Representative males of each of six systellopine genera, dorsal view. 12, Chilodiplus weiri Allsopp, 1993 (photograph by CSIRO). 13, Enamillus pilicollis (Sharp, 1877). 14, Prochelyna heterodoxa Burmeister, 1855. 15, Sarothromerus sharpi (Blackburn, 1905). 16, Sphyrocallus brunneus Sharp, 1877. 17, Systellopus obtusus Sharp, 1877. 18, Antennal club of male Sarothromerus sharpi (Blackburn, 1905).