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

Abstract

While <i>Wolbachia</i>, 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 for <i>Wolbachia</i> horizontal transmission, using ant crickets and their host ants as the model system. We compared prevalence and diversity of <i>Wolbachia</i> across multiple ant cricket species with different degrees of host specificity/integration level. Our analyses revealed at least three cases of inter-ordinal <i>Wolbachia</i> transfer among ant and ant crickets, and also showed that ant cricket species with high host-integration and host-specificity tend to harbor a higher <i>Wolbachia</i> prevalence and diversity than other types of ant crickets. This study provides empirical evidence that distribution of <i>Wolbachia</i> across ant crickets is largely attributable to horizontal transmission, but also elucidates the role of intimate ecological association in successful <i>Wolbachia</i> horizontal transmission.