Tachina fera prefer forest edges, forests, natural gardens, large parks and open countryside. They can usually be found on flowers, looking for nectar. Tachina fera are diurnal flies. They are active from April to October.
|Adult Tachina fera feed on the nectar of flowering plants and on honeydew, while their larvae live off the body tissue of different caterpillars. The females lay their eggs near the caterpillars. The larvae immediately hatch from their eggs and penetrate the host caterpillars. The caterpillars die because the larvae feed on their inner tissue. The larvae are parasitic on the caterpillars of the gypsy moth (Lymantria dispar), the black arches (Lymantria monacha), and the pine beauty (Panolis flammea).|