Transmission, Tropism, and Biological Impacts of Torix Rickettsia in the Common Bed Bug Cimex lectularius (Hemiptera: Cimicidae)

The torix group of have been recorded from a wide assemblage of invertebrates, but details of transmission and biological impacts on the host have rarely been established. The common bed bug is a hemipteran insect which lives as an obligatory hematophagous pest of humans and is host to a primary symbiont and two facultative symbionts, a BEV-like symbiont, and a torix group . In this study, we first note the presence of a single strain in multiple laboratory bed bug isolates derived from Europe and Africa. Importantly, we discovered that the has segregated in two laboratory strains, providing infected and uninfected isogenic lines for study. Crosses with these lines established transmission was purely maternal. Fluorescence hybridization analysis indicates infection in oocytes, bacteriomes, and other somatic tissues. We found no evidence that infection was associated with sex ratio distortion activity, but infected individuals developed from first instar to adult more slowly. The impact of on fecundity and fertility resulted in infected females producing fewer fertile eggs. However, we could not find any evidence for cytoplasmic incompatibility associated with presence. These data imply the existence of an unknown benefit to carrying that awaits further research.