Opatrini Brullé, 1832 is the most species-rich tribe in the subfamily Blaptinae Leach, 1815. In this study, a preliminary phylogenetic relationship among 14 species of five genera of Opatrini is hypothesized based on mitochondrial gene (COI) fragment. Based on the phylogenetic topology and the results of three molecular species delimitation analyses, three larval specimens are assessed for the adults. Additionally, the larvae of these three species are described and illustrated: Gonocephalum bilineatum (Walker, 1858), Gonocephalum gracile (Bates, 1879), and Mesomorphus latiusculus Chatanay, 1917.