Concatenated ML phylogeny for Wolbachia , based on four genes ( wsp , ftsZ , groEL , and trmD ). Thirty-six unique strains are shown. Sample code (Additional file 1) and host species name in which each strain was detected are indicated (for abbreviations see legend Figure 2). ML bootstrap values (top number, bold) and Bayesian posterior probabilities (bottom number, plain) are depicted (only values larger than 50 are indicated). * = the topology within this clade is slightly different for the MrBayes topology. The bar at the bottom indicates a branch length of 10% likelihood distance. Independent phylogenies for each gene are depicted in Additional file 3.