The first instar larva, or triungulin, of Stenodera puncticollis (Chevrolat, 1829) is described. Its characters indicate that Stenodera is the most primitive member of the subfamily Nemognathinae and support the recognition of the monotypic tribe Stenoderini, as previously proposed on the basis of adult morphology. The bionomic information on this genus is summarized, and an annotated catalogue and key to the species based on adults are presented