Caterpillars of cabbage moth (Mamestra brassicae L.) pupated in the soil in depth 6 +- 0.3 cm (range 4-10 cm). At the same conditions parasitized caterpillars (by ichneumonid Exetastes cinctipes Retz.) entered the soil on average about 1.3 cm shallower (P lt 0.01), i.e. larvae of parasitoid formed cocoons in depth 4.7 +- 0.3 cm (range 2-10 cm). As far as the difference in depth of entering parasitized and non-parasitized caterpillars in the soil is little, difference in temperatures, which affect the development of both species in the soil, is minimal.