A detailed study of the abdominal external morphology of both sexes of Thyridia psidii cetoides (Rosenberg & Talbot, 1914) is presented. The material for this research was obtained at the city's plant nursery "Horto Florestal de Curitiba", Paraná, Brazil; mainly by rearing eggs and larvae collected on Cyphomandra betacea (Canavilles) Sendtner, 1845 (Solanaceae). When possible, the results obtained were compared with those already available in the literature concerning other Nymphalidae subfamilies morphology (Brassolinae, Morphinae and Danainae); the most striking feature being the asymmetrical valvae of the male and the length and faint sclerotinization of the third abdominal sternite in both sexes. A resume containing the main morphological differences to other nymphalid subfamillies, found throughout this research concerning head, thorax and abdome, is presented.

A detailed study of the thoracic external morphology of both sexes of Thyridia psidii cetoides (Rosenberg & Talbot, 1914) is presented. The studied material was obtained at the city's plant nursery "Horto Florestal de Curitiba", Paraná, Brazil; mainly by rearing eggs and larvae collected on Cyphomandra betacea (Canavilles) Sendtner, 1845 (Solanaceae). When possible, all the results obtained were compared with those already available in the literature concerning other Nymphalidae subfamilies morphology (Brassolinae, Morphinae, and Danainae); the most striking feature being the almost totally transparent lateral faces of the thoracic mesoscutum in both sexes.

A detailed study of the morphology of the head of Thyridia psidii cetoides (Rosenberg & Talbot, 1914) (Nymphalidae, Ithomiinae) adults from both sexes is presented. The material was obtained at the city's plant nursery "Horto Florestal de Curitiba", Paraná, Brazil; mainly by rearing eggs and larvae collected there on Cyphomandra betacea (Canavilles) Sendtner, 1845 (Solanaceae). When possible, all the results obtained were compared with those already available in the literature concerning external morphology studies pertinent to other Nymphalidae subfamilies (Brassolinae, Morphinae and Danainae).