Nyssicus sp. Click here for a larger view

Diagnosis.--Key characters: Ommatidial size coarse (Fig. 39b); prosternal process widened, not planar, expanded apically (Fig. 18); mesal antennal spines present (Figs. 8b, 9b); elytral humeri without tooth at epipleural margin; pronotum with impunctate regions; femoral carinae absent; procoxal cavities widely open laterally (Fig. 17); lateral projections into mesocoxae from mesosternum absent (Fig. 20); profemoral apices rounded (Fig. 26); meso- and metafemoral apices spinose (Figs. 8c, d, 9c, d, 25a); pronotum with distinctive circular callus at base (Fig. 12f); strongly acute lateral pronotal tubercles (Figs. 12f, 41a); profemora clavate or clavate and pedunculate (Figs. 37a, b); meso- and metafemora clavate and pedunculate (Fig. 37a); tibial carinae present; elytral apices moderately to strongly bispinose. Length: 10-21 mm.

Distribution and Diversity.--Bolivia, northern South America to Costa Rica. Seven species.

Discussion.--Nyssicus is among several groups of South American genera comprising an unresolved polytomy (Fig. 50). More study of South American genera needs to be undertaken to fully understand its relationships.

Nyssicus, with its very distinctive pronotum with basal callus and acute lateral tubercles, elytra with pale, raised fasciae, and strongly spinose meso- and metafemoral apices, is easy to recognize.