Abstract.  Using DNA sequences of nuclear ribosomal (18S) and mitochondrial (cytochrome oxidase I) genes (a modified DNA barcoding approach), we positively identify, for the first time, larvae of hetaeriine Histeridae. Species in this subfamily occur as obligate associates of social insect colonies, particularly those of neotropical army ants. Of several larval specimens collected from bivouacs of Eciton burchelli, we identify the two larval instars of Paratropinus scalptus, and discuss a quite different first instar larva near Euxenister. The larvae are described and illustrated, with attempts to homologize all chaetotaxy to other known histerid larvae. Phylogenetic trees for 18S and cytochrome oxidase I, for over twenty hetaeriine taxa, are compared with each other and with a previous hypothesis of relationships in the subfamily.