Outline of the experimental design. Eight standard (yeast-limited) vials and 5 yeast-supplemented vials were set up for each hemiclone family, consisting of 5 test females and 5 randomly sampled wild-type males. Females were collected at emergence (vial 1), transferred to a new vial 2 days later (vial 2) and then into vial 3 after 2 more days. Counts of emerging offspring were conducted for vials 3 – 7, with females transferred every 24 hours between these vials. Injections were carried out during the transfer of females from vial 3 to vial 4. Females receiving an injection of live Providencia rettgeri were homogenized 28 hours after injection and resistance quantified from bacterial counts. For each hemiclone, two vials were set up in each environment to evaluate resistance. Fecundity in vial 3 was used to evaluate the cost of immunological maintenance. Deployment costs were evaluated by comparing pre-challenge fecundity (vial 3) to post-challenge fecundity (vials 4–7). Dry mass was estimated for females collected at emergence and for females collected at the end of the experiment (exiting vial 7). Females from the three vials used in an analysis of constitutive gene expression were frozen at the time of injections. Data on gene expression is being published elsewhere. See text for details on the analyses.