Gymnocychramus, Lea, 1921

Lawrence, John F. & Kirejtshuk, Alexander G., 2019, Review of the Australian Cyllodini (Coleoptera: Nitidulidae: Nitidulinae), with descriptions of new taxa, and notes on the genus Macleayania (Nitidulini), Zootaxa 4544 (3), pp. 301-334 : 324

Key to the species of Gymnocychramus

1. Colour primarily dark reddish-brown or black ( Fig. 6 ); prothorax wider than combined elytra; sides of pronotum broadly rounded and sides of elytra straight and slightly converging almost to apex; macropunctures on elytra placed more sparsely within longitudinal rows, the distances between them usually greater than a puncture diameter; prosternum strongly tumid; mesal lobe at apex of mentum subacute; ventral surfaces with a number of large, elongate-oval pits lining postmesocoxal lines and anterior edges of metacoxal cavities and occurring on all abdominal ventrites; dorsal lobe of penis ( Figs 62–63 ) about as long as ventral lobe, deeply incised, with small tooth at base of incision; total length 4.70–6.20 mm (mean 5.54).................................................................................................... G. politus Lea

- Colour primarily reddish-orange, with elytra black ( Figs 12, 23 ); prothorax as wide as or slightly narrower than combined elytra; sides of prothorax and elytra evenly, continuously curved; macropunctures on elytra placed more densely within longitudinal rows, the distances between them often less than a puncture diameter; prosternum weakly convex; mesal lobe at apex of mentum broadly rounded; ventral abdominal pits, if present, very small; dorsal lobe of penis ( Figs 60–61 ) much shorter than ventral lobe, apically acute, not incised and without tooth; total length 3.00–5.00 mm (mean 3.98)...... G. bicolor sp. nov.

Figures

FIGURES 1–11. Habitus: 1–6, dorsal: 1, Camptodes aff. humeralis (Brullé), bicoloured (5.0 mm); 2, Cyllodes ruficeps (Reitter) (3.1 mm); 3, Camptodes aff. humeralis (Brullé), unicoloured (5.2 mm); 4, Coxollodes loriai (Grouvelle) (1.9 mm); 5, Cyllopallodes limbatus (Reitter) (2.9 mm); 6, Gymnocychramus politus Lea (5.0 mm). 7–11, lateral: 7, Camptodes aff. humeralis (Brullé), bicoloured; 8, same, unicoloured; 9, Cyllopallodes limbatus (Reitter); 10, Cyllodes ruficeps (Reitter); 11, Coxollodes loriai (Grouvelle). Fig. 10 from Lawrence & Ślipiński (2013). All figures © CSIRO, Australia.

FIGURES 59–69. Genitalia: 59, Camptodes aff. humeralis (Brullé), apex of Ovipositor, ventral; 60–61, Gymnocychramus bicolor sp. nov., apex of penis: 60, dorsal (arrow pointing to apex of dorsal lobe); 61, same, lateral; 62–63, Gymnocychramus politus Lea, apex of penis: 62, dorsal; 63, lateral; 64–67, Macleayania vesca (Olliff): 64, apex of tegmen, dorsal; 65, base of tegmen, dorsal; 66, apex of penis; 67, apex of penile strut; 68–69, Macleayania amphotiformis (Reitter): 68, base of tegmen; 69, apex of penile strut. All figures © CSIRO, Australia.

FIGURES 12–23. Habitus: 12, Gymnocychramus bicolor sp. nov. (4.0 mm), dorsal; 13, Pallodes beccarii Grouvelle (3.0 mm), dorsal; 14, same, ventral; 15, Pallodes nigroapicalis sp. nov. (2.8 mm), dorsal; 16, same, lateral; 17, same, posterodorsal; P. beccarii, dorsal, teneral (2.5 mm); 19, P. beccarii, ventrolateral; 20, Macleayania vesca (Olliff) (3.3 mm), dorsal; 21, M. amphotiformis (Reitter) (4.2 mm), dorsal; 22, same, ventral; 23, G. bicolor, lateral. Fig. 20 from Lawrence & Ślipiński (2013). All figures © CSIRO, Australia.