induces strong cytoplasmic incompatibility in a predatory insect.

, a group of intracellular bacteria found in eukaryotes, exhibits diverse lifestyles, with some acting as vertebrate pathogens transmitted by arthropod vectors and others serving as maternally transmitted arthropod endosymbionts, some of which manipulate host reproduction for their own benefit. Two phenotypes, namely male-killing and parthenogenesis induction are known as -induced host reproductive manipulations, but it remains unknown whether can induce other types of host manipulation. In this study, we discovered that induced strong cytoplasmic incompatibility (CI), in which uninfected females produce no offspring when mated with infected males, in the predatory insect (Hemiptera: Miridae). Molecular phylogenetic analysis revealed that the strain was related to , a common insect endosymbiont. Notably, this strain carried plasmid-encoded homologues of the CI-inducing factors (namely -like and -like genes), typically found in , which are well-known CI-inducing endosymbionts. Protein domain prediction revealed that the -like gene encodes PD-(D/E)XK nuclease and deubiquitinase domains, which are responsible for -induced CI, as well as ovarian tumour-like (OTU-like) cysteine protease and ankyrin repeat domains. These findings suggest that and endosymbionts share underlying mechanisms of CI and that CI-inducing ability was acquired by microbes through horizontal plasmid transfer.