Key to species of Mesomphalia Hope

1 Elytra, in combination, with two discrete patches of yellowish-brown setae: one pair below the humeral angles and a pair at the apical third of the disc.................................................................................. 2

- Elytra in combination without four well-defined patches of setae............................................... 6

2 Elytral disc without macroreticulation..................................................................... 3

- Elytral disc with glabrous macroreticulation............................................................... 5

3 Dorsum elongate, about 1.3x wider than long, with shiny surface; extreme outer margin of pronotum and elytra with flat lateral edges (Figs. 105–106)........................................................... M. sublaevis Boheman, 1850

- Dorsum subcircular or circular, less than 1.3x wider than long, with matt surface; extreme outer margin of pronotum and elytra with lateral edges not flats.............................................................................. 4

4 Pronotum with a pair of circular setose patches; elytra with fine and sparse punctures, three circular depressions at the basal third, followed by a continuous depression next to the apical margin and patches of decumbent, long, yellowish-brown setae: one crescent shaped, under the humeral angles, and a band of setae leading from it, parallel to the elytral suture at the apical third of the disc (Figs. 107–109)............................................ M. spaethi Simões & Monné sp. nov.

- Pronotum with a pair of subtriangular setose patches; elytra with coarse and dense punctures, without depressions, with a pair of subtriangular macules adorned by setae under the humeral angle and one pair of elliptical setose patches at the junction of the disc and lateral margin, near the apex (Figs. 110–113).................................. M. turrita (Illiger, 1801)

5 Elytral macroreticulation conspicuous, forming row of foveae, parallel to the suture and posterior to gibbosity. Elytral disc with punctation concentrated at apical two-thirds (Figs. 114–116).......................... M. subnitens Spaeth, 1917

- Elytral macroreticulation disorganized posterior to gibbosity, blending in with punctation. Elytral disc with uniformly distributed punctation (Figs. 117–119)................................................ M. sexmaculosa Boheman, 1856

6 Pronotum with a pair of yellowish-brown setose patches, surrounded by an orangish-red ring and an outer yellow ring (Figs. 121–123)...................................................................... M. tumidula Boheman, 1850

- Pronotum with patches of unicolored setae or without well-defined patches...................................... 7

7 Elytra with scattered circular black depressions, darker than surrounding integument............................... 8

- Elytra without circular depressions that are darker than surrounding integument................................... 9

8 Elytra with pubescence in thin separate bands, next to the margins of the disc, under the humeral angle and next to the apex (Figs. 98–100, 124–130)........................................................ M. variolaris Boheman, 1850

- Elytra with pubescence more expanded at the basal third, except glabrous humeral angles, continuing to an irregular band creating a large, and round area at the apical third and a conspicuous triangular area next to the apex (Figs. 131–137)....................................................................................... M. denudata Boheman, 1850

9 Elytra with conspicuous macroreticulation, completely or partially adorned by setae................................ 10

- Elytra without macroreticulation......................................................................... 12

10 Pronotum with pubescence restricted to two subtriangular spots of setae (Figs. 101–104)...... M. gibbosa (Fabricius, 1781)

- Pronotum with pubescence distributed on the entire surface or restricted to faint arcs on disc........................ 11

11 Elytral macroreticulation shining, forming large and well-demarcated depressed areas; elytral punctures coarse and sparse, except at the anterior margin of the gibbosity and antero-lateral angle; elytral setae sparse, denser at macroreticulation next to the basal margin, at the parascutelar disc, under the humeral angles, at the post-median region, and at the basal third (Figs. 138–143)..................................................................... M. retipennis Boheman, 1850

- Elytra with dull macroreticulation, forming small foveae; elytral punctation fine and dense, reaching the margins; elytral setae dense and whitish (Figs. 144–147)................................................. M. latipennis Boheman, 1856

12 Elytra with continuous brownish-yellow setae, along basal third except for humeral angle, followed by two glabrous diamondshaped areas continuing in an irregular band, forming a large, rounded area at apical third and another triangular area at apex (Figs. 148–151)................................................................ M. nudoplagiata Spaeth, 1901

- Elytra with isolated tufts of whitish setae................................................................. 13

13 Pronotum with two setose arcs. Elytra with punctation moderately dense and coarse; and setae short, whitish and sparse.................................................................................. M. ampliata Boheman, 1850

- Pronotum with setae not forming arcs. Elytra with sparse and smooth punctures and seven whitish setal tufts next to the margin and sparse after the suture................................................... M. albofasciculata Boheman, 1856