Malagasy Pseudosystolederus sikorai Günther is Paratettix voeltzkowiana Saussure (Orthoptera, Tetrigidae)

The Madagascar boulder pygmy grasshopper, Pseudosystolederus sikorai Günther, 1939, syn. nov. (Tetrigidae: narrow-vertex taxa related to Xistrella ), which is the type species of Pseudosystolederus Günther, 1939, is found to be conspecific with Paratettix voeltzkowiana Saussure, 1899. Thus, Pseudosystolederus voeltzkowianus (Saussure, 1899), comb. nov. becomes a new combination and has priority. The Madagascar boulder pygmy grasshopper is unique in its large tooth on the ventral margin of the mid femur and is relatively common on and around large boulders surrounding rivers throughout Madagascar. Photographs and measurements of the syntypes of P. sikorai syn. nov. and P. voeltzkowianus comb. nov. are presented together with new records, photographs of the species in its natural habitat, photographs of the habitat itself, and a brief discussion on the position of the genus Pseudosystolederus within Tetrigidae. Morphopoides lesnei Günther, 1979, comb. rev. is moved from Pseudosystolederus to the original combination.