Most grasshopper species have simple and similar life cycles and histories; however, different environmental and ecological factors have different effects on their distribution, sexes, and developmental stages, with effects varying among species. If we are to conserve grasshoppers, we need to understand their ecology and life histories. The aim of this study was to investigate aspects of the life histories and ecology of two recently described co-occurring, congeneric species of wingless grasshoppers, Eremidium armstrongi (Brown, 2012) and Eremidium browni Otte & Armstrong, 2017, at the Doreen Clark Nature Reserve near Pietermaritzburg, South Africa. These two species have limited extents of occurrence, only being known from an endangered forest type in parts of the midland area of KwaZulu-Natal Province, South Africa, and therefore may need conservation action to ensure their long-term survival. No significant differences in the abundances of the two Eremidium grasshoppers were found, but their phenologies differed, with the adults of E. armstrongi being present before the adults of E. browni, with some overlap in presence over time. The Eremidium grasshoppers were only found in the forest and were more abundant in the forest margin. The Eremidium grasshoppers fed on soft plants from several families. Information on dietary differences between the species is required to determine whether there is potential competition between them. An adult E. browni female kept in an ex situ terrarium laid eggs in the soil, and nymphs took approximately two months to hatch.