One of a three-part series, this bulletin presents techniques developed at CIMMYT and other locations for mass rearing and infestation with the fall armyworm (Spodoptera frugiperda) for screening and development of maize with host plant resistance to the insect. The author explains techniques for colony establishment and maintenance, gives requirements for efficient mass rearing, describes methods of efficient field infestation, and covers rating scales used to evaluate damage and identify resistant genotypes. The techniques described in this publication are probably adaptable to other Lepidopterous pest species, crop species, and breeding efforts16 pages