Figure 3

Phylogenetic analysis of ‘ S. philanthi ’ isolates in respect to the sequences obtained from field-collected antennal samples. Antennal isolates are indicated by their strain designation as explained in the Methods section (first three letters indicate host species), and the respective host species is additionally given behind each clade. Sequences directly obtained from beewolf antennae are indicated by “CaSP” and were obtained from a previous study [28]. The tree was reconstructed using nearly complete 16S rRNA genes and 660 bp-long gyrB gene fragments; values at the nodes indicate Bayesian posterior probabilities. Geographic distribution of beewolf taxa and the origin of isolated symbionts are indicated by branches of different colours on phylogenetic tree: Africa (yellow), Europe (red), mixed African/ Eurasian distribution (dashed yellow/red line), North and South America (purple and blue, respectively). Bacteria used as outgroups to root the tree are indicated in Additional file 4: Table S4. The discrepant phylogenetic placements of Philanthus albopilosus symbiont sequences from clones and isolates, respectively, are highlighted by grey boxes.