(a) Distributions of the SIBELIUS SNIa host star-formation rates. In light blue, we show the star-formation rate distribution of the entire SIBELIUS-DARK galaxy sample. (b) SNIa rate per galaxy as a function of the star-formation rate. The continuous line is from Smith et al. (2012, fig. 4). (c) SNIa hosts on the star-formation rate – stellar mass plane, coloured according to their specific star-formation rate. The black dashed line separates highly from moderately star forming galaxies in Smith et al. (2012, fig. 2). The dashed dotted one encloses all weakly star-forming hosts in that plot. (d) SNIa rate per galaxy as a function of host stellar mass. The lines are from Smith et al. (2012, fig. 3). The error bars indicate |$1\sigma$| uncertainty over the hosts in 300 Poisson realizations.