The fall armyworm Spodoptera frugiperda is the larval life stage of a moth. This worm is a pest that can wreak havoc with crops if left to multiply. Biocontrol methods are currently developped to avoid the use of toxic pesticides. Agronomists Figueiredo et al. show that the yield of organic maize can be increased by 19% using the wasp Trichogramma pretiosum and a pheromone sex trap.