Twelve new species of Tomoplagia reared from capitula of Asteraceae collected in southern and southeastern Brazil are described (T achromoptera n. sp., T aczeli n. sp., T bicolor n. sp., T brasiliensis n. sp., T cipoensis n. sp., T dimorphica n. sp., T grandis n. sp., T interrupta n. sp., T matzenbacheri n. sp., T rupestris n. sp., T variabilis n. sp., and T voluta n. sp.). Five of these species have highly atypical wing markings, differing from the usual pattern for the genus, which includes five oblique yellow bands. Aberrant wing patterns were previously known in only three species. All the new species were reared from capitula of Vernonieae, confirming this Asteraceae tribe as the main host group of Tomoplagia species. Of these new species, five are specialists on the Lychnophorinae, a Vernonieae subtribe endemic to campo rupestre vegetation, which occurs on tops of mountain chains in central and southeastern Brazil. These species of Tomoplagia are probably restricted to the small ranges of these host plants. An addedum to the most recent key to species (Aczel 1955a) is provided, including couplets to all of the species with modified wing patterns.332189211