C. luridus distinguished from C. inhalatus because the vestiture is pinkish or grey, and always lighter on head, venter and legs; the sides of the pronotum are less curved than in the other species, and the elytra more rugose, with supernumerary striae always distinct.
Mouthparts of this species were described in Díaz et al. (1990a b) and characters of vestiture in Coscarón et al. (1991).
A key to species of Cyrtomon is provided in Lanteri (1990a) and Lanteri & del Río (2016).
Microctonus sp (Hymenoptera: Braconidae) is a parasitoid of C. luridus that has been investigated for its biological control in Brazil (Tironi et al. 2004).
Solanum viarum Dunal in Misiones, Argentina (Lanteri et al. 2002a); Solanum mauritianum Scopoli, Cestrum intermedium Sendt. and Duboisia sp (Solanaceae) in Paraná, Brazil (Tironi et al. 2005). Duboisia sp is a medicinal plant introduced in Brazil from Australia. The weevil is adapted to this plant and the larvae feed on the roots causing 100% damage in Arapongas, Paraná state (Tironi et al. 2005). It is also associated with Eucalyptus spp (Myrtaceae) in São Paulo (Silva et al. 1968).
Associated with the vegetation of the Atlantic and Paranaense forests.