The experimental procedure A the priming procedure was to inject females either with a low dose of living S. enterica (SAP, in red) or sterile LB Broth (LBP, in grey). The non-primed (NP, in green) females did not receive the first injection B SAP, LBP, and NP females received the second, LD50 injection of living S. enterica. Control females (in black) were never injected C all females (SAP, LBP, NP, control) were allowed to reproduce individually in a box with one virgin, non-injected male (brown woodlouse). We checked the survival rates of females, the number of clutches (1 or 2), the time to produce each clutch (number of days), and the number of offspring in each clutch D regularly, we sampled and dissected females that produced the second clutch to analyse haemocytes and β-galactosidase activity. Brackets indicate that not all females produced a second clutch. Approximately eight months later, we waited for the last females to produce their second clutch, and then sampled and dissected the remaining females that produced only one clutch.