The last-instar larvae of the tribe Pyraustini of America north of Mexico are revised. Thirty-five species and nineteen genera are included, Munroeodes Amselone species, Saucrobotys Munroe- one species, Epicorsia Htibner- one species, Oenobotys Munroe- one species, Crocidophora Lederer- one species, Ostrinia HtVbner- three species, Fumibotys Munroey one species, Eurrhypara Httbner- one species, Phlyctaenia Htlbner- one species, Nealgedonia Munroe- one species, Mutuuraia Munroe- one species, Anania Hubner- one species, Hahncappsia Munroefive species, Achyra Guenee- two species, Helvibotys Munroa-^-one species, Sitochroa Hubner- one species, Uresiphita Hubner- one species, Loxostege Hubner- five species, Pyrausta Schrank- six species. The last-instar larvae of twelve species are described for the first time, Munroeodesthalesalis (Walker), Epicorsia oedipodalis (Guenee), Oenobotys vinotinctalis (Hampson), Crocidophora pustuliferalis Lederer, Nealgedonia extricalis (Guenee), Uresiphita reversalis (Guenee), Pyrausta dapalis (Grote), P. fodinalis (Lederer), P. sp. near laticlavia (Grote and Robinson), P. orphisalis Walker, P. tyralis (Guenee), P. unifascialis (Packard). The relationships between the adults and the larvae are discussed. Key to the genera for last-instar larvae is given, and the larval characters illustrated.