The fall armyworm, Spodoptera frugiperda, as with many noctuid moths, is a serious agricultural pest in the United States. Researchers often use pheromone traps to monitor for the presence of economically important noctuid pests. Pheromone traps may attract more than one species and samples often degrade, making morphological identification of some adult noctuid species nearly impossible. A molecular diagnostics protocol using polymerase chain reaction, restriction fragment length polymorphism (PCR-RFLP) was developed in order to distinguish the fall armyworm from six other noctuid species commonly found in Arkansas. A 611-bp region of the mtDNA COI, COII genes was amplified using PCR and then sequenced. The restriction enzymes Dra I, Alu I and Nla III had specific restriction sites that distinguished the seven noctuid species. This proved to be a reliable, quick and economical technique for identifying the fall armyworm as well as six other noctuid species.