The current work presents the description of five new cricket species for the genus Phalangopsis Serville, 1831 found in Brazilian caves in the Amazonas, Mato Grosso and Pará states, northern Brazil. The morphology of the phallic complex was used as the main criterion for distinguishing the species. In addition, we present data on the natural history and ecology of the new species as well as hypothesis about the variations of tegmina size in relation to the subterranean lifestyle for the genus. Finally, we provide a pictorial key based on adult males for the Phalangopsis species.

A new cricket species of the genus Endecous Saussure, 1878 is described in the present work found in the speleological province of Arcos-Pains-Doresópolis, which belongs to the limestone group Bambuí, Brazil. Moreover, the spatial distribution of the new species was related to the species Eidmanacris sp., which co-occurs with the former in several caves. Relationships between species abundance and horizontal projection, number of entrances and environmental stability of the caves where these species coexist were evaluated. The presence of bilateral symmetry in individuals of Endecous painensis n. sp. perhaps due to environmental stress caused by mining activities surrounding the cave was also tested. Endecous crickets are commonly observed in the caves, for which the preference by distinct microhabitats and generalist strategies may be key factors explaining colonization and segregation in relation to other cricket species in subterranean habitats. The generalist lifestyle of the here described species may attenuate the effects environmental stresses over development.

The genus Endecous (Orthoptera, Grylloidea, Phalangopsidae), commonly found in caves, comprises more than 20 species, grouped into three subgenera: E. (Endecous), E. (Pedroecous) and E. (Notendecous). In this study, from differences observed mainly in the male genitalia, we describe a new subgenus—Endecous (Ramalhoecous) n. sp.—as well as three new species—E. (R.) infernalis n. sp., E. (E.) zin n. sp. and E. (E.) zaum n. sp.—all of them collected in caves in the Serra do Ramalho region, Northeastern, Brazil. We also briefly discuss some troglomorphisms verified in one of the new species: E. (R.) infernalis n. sp.