The biology and morphology of all stages of a new species of Psychidae from Panama, Perisceptis carnivora Davis (Lepidoptera: Psychidae), are described. The larvae of this bagworm are unusual in being obligatory predators, feeding on a broad range of living arthropods, including Arachnida, Coleoptera, Homoptera, Hymenoptera, Neuroptera, and Orthoptera. Probably because of their relative abundance, ants seem to be the most frequent prey. The eggs of this species are protected in a manner that may be unique for insects. Soon after an egg exits the female ovipore, it is wrapped inside a small cocoon-like case constructed of specialized setae from the seventh abdominal segment. Hypotheses as to how these eggs are wrapped and how the cases may protect the eggs are proposed.