The life history and feeding habits of larval Rivellia melliginis (Fitch) are presented. Courtship and mating occur on or near the host plant, black locust, Robinia pseudoacacia L.; eggs are placed in clusters of 10–20 in soil below the host plant; larvae attack and destroy the nitrogen-fixing root nodules, each larva destroying up to 6 nodules; overwintering occurs as a fully grown larva in diapause; and puparia are formed in soil. There are two generations a year in northeastern Ohio. It is suggested that larval feeding affects the nitrogen-fixing capability of black locust, a species widely used in reclamation of stripmined lands.