A factorial experiment utilizing bovine manure type, time of day, and distance from a barn as the independent variables, showed that the number of house fly and face fly pupae recovered from exposed samples varied in response to their preferred habitat. Analysis of variance showed distance from a barn and manure type to be significant factors influencing house fly pupal recovery while showing all 3 factors to be significant in influencing face fly pupal recovery. Curvilinear regression curves showed the greatest recovery of face fly pupae to be from grass manure and an equal mixture of grass and grain manure exposed at 100, 200, and 300 m from the barn between 9:00 a.m. and noon. House fly pupae were recovered almost exclusively from grain manure samples exposed at 0 m from the bam. Approximately equal quantities of house fly pupae were recovered from the samples exposed at 9:00 a.m., noon, and 3:00 p.m.