There are few known predators and parasitoids of Ochrogaster lunifer:
Dermestid beetles (Dermestidae spp.) are the dominant predators, and eat the eggs and first instar caterpillars within the egg mass. Dermestid larvae are generalist feeders, feeding on dry material of animal origin, such as insect remains.
Tachinid flies (Tachinidae) are parasitoids of O. lunifer larvae (caterpillars) and are commonly observed flying around O. lunifer nests in March and April. The female fly finds a hole in the silken nest and enters. She deposits one or several eggs on the head of older, larger caterpillars. The fly larva develops and pupates in the processionary caterpillar/pupa, eventually emerging from it instead of a moth (see below).
Chalcid wasps (Chalcididae) are also parasitoids of O. lunifer caterpillars. The females lay their eggs on or in the processionary caterpillar eggs within which the wasp develops, eventually killing its host.