Key to known species of subgenus Merocratus from China

1. Pronotum metallic orange or metallic yellow with two smaller, black, more or less rounded spots not narrowed posteriorly, the range begins at the anterior margin and does not exceed 2/3 of the anterior of pronotum (Figure 6 (i, k)); elytra almost monochromatic, without two semicircular metallic green maculae along lateral margins (Figure 2 (a, b)) ........................... ........................... A. (M.) insulaecola Obenberger 1944

− Pronotum metallic green with two larger, black, more or less triangular spots narrowed posteriorly, the range begins at the anterior margin and exceeds 2/3 of the anterior of pronotum (Figure 6 (a, c, e, g)); elytra almost bicolour, with two semicircular metallic green maculae along lateral margins (Figures 1 (a, b), 3(a, b)) .......................... 2

2. Lateral margins of pronotum widens and narrows irregularly, widest near sixth of the base or near midlength (Figure 6 (e, g)); terminal part of elytra without two broad longitudinal metallic green stripes (Figure 3 (a, b)); abdomen metallic green (Figure 3 (c, d)); aedeagus broader, apical portion of each paramere expand slightly (Figure 9 (d, e)) ................................................... ................................................... A. (M.) tamdaoensis Bílý, 1998

− Lateral margins of pronotum widens and narrows regularly, widest near midlength (Figure 6 (a, c)); terminal part of elytra with two broad longitudinal metallic green stripes along the suture (Figure 1 (a, b)); abdomen nearly black (Figure 1 (c, d)); aedeagus slender, apical portion of each paramere expand strongly (Figure 9 (a, b)) .. ............................................................................................ A. (M.) zhengyucheni Qi & Song, sp. n.