Relative Wolbachia titers. Barplots showing the ratio of Wolbachia-specific reads to Drosophila-specific reads for each library in historic and contemporary samples. The fill color (and hue) depicts the Wolbachia type in the recent samples. Here and in all other figures, wMel is shown in blue (dark hue) and both the wMelCS and the wMelPOP type are shown in red (lintermediate hue). The yet undetermined Wolbachia type in historic samples with uncertain infection status is shown in gray (light hue) and uninfected samples are highlighted in white.