Fig. 1

Phylogenetic inference and main host and vector association of B. burgdorferi sensu lato The phylogeny reconstructed with BEAST v1.7.5 [26] is based on 114 orthologous single copy genes. Genospecies names and host associations are indicated next to the cluster. As huge number of host species can serve as reservoirs for Borrelia [4], for sake of clarity, we used a crude host association referring to rodents (indicated by the mouse), birds (indicated by the black bird) and lizards. For the same reason, not all vector associations can be shown. The following vectors are not shown in the phylogeny (which does not mean that they are less important for natural transmission cycles): I. hexagonus (vector of B. afzelii, B. burgdorferi s.s., B. bavariensis), I. affinis (B. burgdorferi s.s., B. bissettiae), I. minor (B. americana, B. carolinensis), I. jellisoni (B. californiensis), I. uriae, I. pavlovskyi (B. garinii), I. stilesi (B. chilensis) and I. granulatus (B. yangtzensis) and I. nipponensis. Note the high posterior probability of internal nodes (within-species node posterior probabilities are not shown for sake of clarity). The scale bar indicates substitutions per site