Key to subgenera of Chrysodema

1 Principal impressions (a) small to moderately large (Figs 96–97, 102–103), not reaching lateral margin of pronotum, sometimes only linear or nearly absent (Figs 100–101)................................................................. 2

- Principal impressions (a) large and rounded, reaching to lateral margin of pronotum, which forms a sharp carina (e) (Figs 98–99).................................................................. Pseudochrysodema Saunders, 1874

2 Basal impressions of pronotum absent (Figs 96, 100)......................................................... 3

- Pronotum with subtriangular, deep and sharply cut basal impression (d) on each side situated approximately at 1/7 width of basal side (Fig. 102)............................................................... Gelaeus Waterhouse, 1905

3 Pronotum without principal impressions or only weakly indicated, medial line absent to weakly indicated, medial impressions absent (Fig. 100); costae on elytra weak, often only indicated or not clearly visible........... Thymedes Waterhouse, 1905

- Pronotum with distinct principal impressions (a) and usually with medial line as well as medial impressions (b), however, the latter can be very shallow or partly reduced (Figs 96–97); costae on elytra usually clearly visible..................................................................................... Chrysodema Laporte de Castelnau & Gory, 1835