The fall armyworm, Laphygma frugiperda, was reared through 20 successive generations under laboratory and greenhouse conditions without apparent change in the insects'' appearance, habits, or vigor. Adults, fed 10% sucrose and 10% honey, were maintained in a 60x35x35-cm screen=and=glass cage. They oviposited on pots of corn seedlings and folded paper toweling. Eclosion occurred in 4 to 5 days and larvae either were allowed to remain or corn seedlings, or second instar larvae were transferred individually to vials containing a laboratory-prepared diet. Pupation occurred in the soil of the pot or in the vials when larvae were about 12 days old. After 10 to 12 days adults emerged from the moist sawdust in which pupae were placed. Oviposition began 2 to 3 days later.