There are one species of Gea and seven species of Argiope in the Americas. Distributions of Gea and Argiope species are recorded with new records from South America. Only one new species, A. ericae, from southern Brazil to northern Argentina, was found and is here described. The coloration of the female abdomen of Argiope species differs more than the visible differences of the genitalia. Males are separated by differences in palpi, the attachment of the embolus to stipes, and the shape of the coiled embolus.