Bracon cephi (Gahan) and B. lissogaster Muesebeck are host specific larval parasitoids of the wheat stem sawfly, Cephus cinctus Norton. A reliable source of these parasitoids is needed for inoculative releases into sawfly infested wheat fields in Montana. Large walk-in field screen cages were used to confine sawflies and parasitoids on wheat. Factors affecting the successful establishment of sawflies in wheat and subsequent parasitism were tested. Treatments consisted of cage modifications such as windows for enhancing the amount of light, food sources for parasitoids, increased light plus food sources, and a control. Methods for delivering adult sawflies into the cages were also investigated. The mass rearing cages with the windows had significantly greater sawfly infestation and parasitism when compared to the cages without windows. The sawfly infestation was low the first year, while the percent parasitism was quite high, indicating that the major impediment to mass rearing was obtaining greater sawfly infestation. We obtained higher amounts of infestation and parasitism for the second year when the method of introduction of C. cinctus adults into the rearing cage was changed, and this difference was more obvious than any treatment effects. However, the sex ratio of the mass reared parasitoids was male biased indicating the absence of pre-mated females in the cages. The low number of male parasitoids in the rearing cages probably influenced this outcome. These experiments have taken the goal of mass producing parasitoids for release into sawfly damaged wheat fields of Montana a step closer to practical reality.