Key to species of Nyssicus

1) Outer spine of the elytral apex black....................................................................... 2

– Outer spine of the elytral apex not black, concolor with adjacent area............................................ 5

2(1). Pronotum with blackish macula close to center of anterior margin. French Guiana, Brazil (Pará, Alagoas, Bahia, Espírito Santo, Rio de Janeiro, S„o Paulo)......................................................... N. mendosus Martins, 2005

– Pronotum lacking blackish macula close to anterior margin.................................................... 3

3(2). Internal tubercle of the scape in male placed about middle, wide lobe-shaped. French Guiana ................................................................................................ N. lobatus Tavakilian & Dalens, 2014

– Internal tubercle of the scape in male placed before middle, slender............................................. 4

4(3). Ventral surface of the metafemoral club with abundant setigerous granules. French Guiana, Brazil (Amapá, Amazonas)........................................................................ N. granulatus Tavakilian & Dalens, 2014

– Ventral surface of the metafemoral club with a few setigerous granules. Honduras, Ecuador, Venezuela, Peru, Bolivia, French Guiana, Brazil (Amazonas, Pará, Mato Grosso, Rondônia, Maranh„o)................ N. quadriguttatus (Swederus, 1787)

5(1). Scape in male lacking internal tubercle; apex of the antennomeres III–V blackish; sutural spine slightly shorter than outer spine. Bolivia ...................................................................... N. contaminatus Martins, 2005

– Scape in male with internal tubercle; apex of the antennomeres not blackish; sutural spine much shorter than outer spine... 6

6(5). Anterior margin of the internal tubercle of the scape in male as an extension of the anterior margin of the scape; anterior yellowish elytral macula subtriangular; posterior yellowish elytral macula distinctly longer than wide. Venezuela ................................................................................... N. fernandezi Joly & Martínez, 1981

– Anterior margin of the internal tubercle of the scape in male not as extension of the anterior margin of the scape (internal margin of the scape distinctly concave base and tubercle); anterior yellowish elytral macula subrounded; posterior yellowish elytral macula slightly longer than wide. Honduras, Nicaragua, Costa Rica, Panama ............ N. topographicus (Linsley, 1935)