The purpose of this application, under Articles 23.9.3 and 81.2.3 of the Code, is to suppress ColonychusHarold, 1868 for the purposes of the Principle of Priority and thereby conserve Streblopus Lansberge, 1874 as the valid name of the genus of dung beetles consisting of S. opatroides Lansberge, 1874 and S. punctatus (Balthasar, 1938), in accord with universal current usage. Although made available by Harold in 1868, almost all authors who have cited the name Colonychus have regarded it as unavailable or invalid in favour of Streblopus, the only dissenting author having merely mentioned Colonychus twice in passing more than a century ago. Because no specific name has ever been used in combination with Colonychus, no type species has been fixed for this nominal genus. Nonetheless, our confirmation of the identity of a specimen presumably studied by Harold for his description of Colonychus leaves no doubt that the synonymy between Colonychus and Streblopus is correct. While the conditions of Art. 23.9.1.2 for automatic reversal of precedence are fully met, those of Art. 23.9.1.1 are not; therefore, recourse to the Commission's plenary power is necessary in this instance to maintain nomenclatural stability and universality.