A detailed description of the sap beetle Brachypeplus glaber LeConte (Nitidulidae) is provided, including egg, larval, pupal and adult stages. Rearing and DNA barcoding were used to confirm life stage identifications. This is the first New World Brachypeplus species for which larval and pupal descriptions are available. Characters and character states for larvae, pupae, and adults are discussed at the species and generic levels within the context of phylogenetic revisions at different hierarchical levels.