Relationship between host shift genetic distance and bacterial traits in novel species. Figure 4a – the relationship between interspecific transfer distance and the degree of host offspring sex-ratio distortion achieved by the male-killer (proportion male); the correlation is significant (see text). Figure 4b – the relationship between host shift genetic distance and vertical transmission to host offspring (proportion infected); the correlation is not significant (see text). Data points represent means for each species. A least squares best fit line fitted through the origin (4a) and through 1.0 (4b) is shown for each graph. All interspecific transfections are represented apart from C. septempunctata (for with no offspring resulted): brown, A. decempunctata; blue, P. quatuordecimpunctata; green, C. quatuordecimguttata; red, A. novemdecimpunctata, black; H. quadripunctata, orange; E. quadripustulatus. Error bars show standard errors, where no bar is visible variance was zero (apart from E. quadripustulatus for which n = 1).