A new species of Seira Lubbock, 1869 is described and illustrated. Seiraglabra sp. nov. is the second species described from the municipality of Areia (Caatinga biome) and the seventh from the state of Paraíba, Brazil. Compared with other species of the genus, Seira glabra sp. nov. has some remarkable reductions on dorsal chaetotaxy, specially on the methatorax and first abdominal segment. The most similar species to S.glabra sp. nov. is Seira praiana. Both lack macrochaetae on the first abdominal segment.

A new species of Tyrannoseira Bellini & Zeppelini, 2011 (Entomobryidae) is described and illustrated. Specimens of T. diabolica sp. nov. were collected in Barreira do Inferno, state of Rio Grande do Norte, Brazil. This is the fourth described species in the genus. All males of Tyrannoseira have the femora of the first pair of legs enlarged and slender tibiotarsi, both bearing several spine-like setae. Probably the closest species to T. diabolica sp. nov. is T. sex Bellini & Zeppelini, 2011. They share many similarities in their color pattern and dorsal chaetotaxy.