The agricultural industry largely relies on conventional pesticides to maintain healthy, pest-free crops. Application of conventional insecticides is the go-to method for cultivating important food crops, such as corn and sorghum, free of Spodoptera frugiperda (fall armyworm) infestations. However, conventional insecticides have purported negative environmental and health impacts. Natural plant extracts, such as essential oils, are viewed as a promising alternative to conventional insecticides. In the current study, Dysphania ambrosioides (epazote) essential oil was embedded into an artificial diet and fed at two different concentrations to fall armyworms during a 10-day period. Final weights of the 5% epazote treatment group were statistically less (F₆₃₄₃ = 136.2 p < 0.001) than control groups. The 5% epazote treatment group also experienced the highest mortality rate (62%) of any treatment group (X² = 831.4, DF = 6, p < 0.001). Findings suggest that epazote essential oil has potential as an effective, natural insecticidal ingredient. This research is of importance to the fields of agronomy and health sciences.