Naupactus auricinctus is characterized by the iridescent green or purple-pink scaly vestiture, mostly sparse except on a pair of lateral stripes along the posterior third of pronotum, a transversal stripe across the base of elytra, a longitudinal stripe along 7° elytral interval, and the sides of venter. Microscopic, recumbent setae are mix with scales and a tuft of fine, long, erect setae are present on the apex of elytra.
Antennae are very long; pronotum is subcylindrical, more convex in males than in females; elytra are slightly convex in lateral view, base is almost straight and intervals show transversal rugosities; front femora are darker and distinctly wider than middle and hind femora; and corbels of hind tibiae are absent.
Naupactus auricinctus differentiates from N. condecoratus because there is not a distinct light stripes along the 5º elytral interval, elytra are slightly shorter and more convex in lateral view, striae have smaller punctures, and intervals are less rugose.
N. auricinctus causes damage to Ilex paraguariensis Saint Hill. (Aquifoliaceae) in Argentina (Bosq 1943), and to cotton Gossypium hirsutum L. (Malvaceae) and Casearia sylvestris Sw. (Flacourtiaceae), in Brazil. The latter plant, commonly named “guaçatonga”, has been used in folk medicine in that country, for their properties as antiseptic and anaesthetic.
This species is associated with native vegetation of the Atlantic and Paranaense forests.