Naupactus cinereidorsum differentiates from N. argentatus because the ash-grey scaly vestiture is usually more dense, paler and without silver iridescence. The flanks of the pronotum are more curved and the elytra are shorter than in N. argentatus; punctures of the elytral striae are very distinct and corbels of the hind tibiae are absent.
Naupactus cinereidorsum is also similar to N. denudatus, in size and general body shape, but in the latter the integument is almost nude of scales.
Males are more slender than females.
Medicago sativa L. Glycine max (L.) Merr. (Fabaceae), and Heliantus annuus L. (Asteraceae) (Lanteri et al. 2002a).
It is mainly associated with native vegetation of the Chacoan and Espinal biogeographic provinces.