Evidence for Common Horizontal Transmission of Wolbachia among Ants and Ant Crickets: Kleptoparasitism Added to the List.

WhileWolbachia, an intracellular bacterial symbiont, is primarily transmitted maternally in arthropods, horizontal transmission between species has been commonly documented. We examined kleptoparasitism as a potential mechanism forWolbachiahorizontal transmission, using ant crickets and their host ants as the model system. We compared prevalence and diversity ofWolbachiaacross multiple ant cricket species with different degrees of host specificity/integration level. Our analyses revealed at least three cases of inter-ordinalWolbachiatransfer among ant and ant crickets, and also showed that ant cricket species with high host-integration and host-specificity tend to harbor a higherWolbachiaprevalence and diversity than other types of ant crickets. This study provides empirical evidence that distribution ofWolbachiaacross ant crickets is largely attributable to horizontal transmission, but also elucidates the role of intimate ecological association in successfulWolbachiahorizontal transmission.