Wolbachia Endosymbiont of the Horn Fly (Haematobia irritans irritans ): a Supergroup A Strain with Multiple Horizontally Acquired Cytoplasmic Incompatibility Genes

Horn flies, Haematobia irritans irritans , are obligate hematophagous parasites of cattle having significant effects on production and animal welfare. Control of horn flies mainly relies on the use of insecticides, but issues with resistance have increased interest in development of alternative means of control. Wolbachia pipientis is an endosymbiont bacterium known to have a range of effects on host reproduction, such as induction of cytoplasmic incompatibility, feminization, male killing, and also impacts vector transmission. These characteristics of Wolbachia have been exploited in biological control approaches for a range of insect pests. Here we report the assembly and annotation of the circular genome of the Wolbachia strain of the Kerrville, TX, horn fly ( w Irr). Annotation of w Irr suggests its unique features, including the horizontal acquisition of additional transcriptionally active cytoplasmic incompatibility loci. This study provides the foundation for future studies of Wolbachia -induced biological effects for control of horn flies.