Phylogeny derived from 1.3 kb of 16S rDNA sequence. Parsimony tree (PAUP vers. 4.0b4a). All branches had 100% bootstrap support, except where indicated by numbers on branches. Bold line indicates the lineage which has specialized in manipulating host reproduction, and which has lost the ability to infect vertebrate hosts. Wolbachia host genera are shown in parentheses. Wolbachia sequences used in this analysis were from infections in coleopteran (Diabrotica), dipteran (Drosophila), hymenopteran (Muscidifurax) and filarial worm (Brugia) hosts. Crossed line indicates ancestral loss of the ability to infect vertebrates, and acquisition of reproductive specialization.