Associating adults with other life stages of holometabolous insects (eggs, larval instars, pupae) can be problematic when rearing is challenging or impossible. Lack of associations makes morphological characters present in these life stages inaccessible for scientific study and diagnosis. Rearing is often labor intensive and often impossible when specimens are collected far from the lab on short field trips. Unlike morphological features, DNA sequence data overlaps between life stages suggesting that species-specific diagnostic characters in the sequence may provide a means for associating adults and larvae. We attempted to use sequence data to associate unidentified larvae of diving beetles (Dytiscidae) including several species of Cybister Curtis from India and Namibia, suspected Philodytes umbrinus (Motschulsky) from Namibia, suspected Notaticus fasciatus Zimmermann from French Guiana and suspected Hygrotus diversipes Leach from Wyoming. Unidentified larvae were sequenced for an 806bp fragment of the mtDNA gene Cytochrome oxidase I (COI). Adults of the species that the larvae were suspected to be were also sequenced, as were specimens of numerous closely related species from the same geographic area and suitable outgroup species. Data were analyzed using cladistic and distance analysis to determine whether the sequences convincingly associated larvae with identified adult specimens. In each case, we successfully associated larvae with adults of a known species. We then described the larvae of the species identified making the characters in these immatures available to science for the first time.