Wolbachia facilitates the reproduction of a parthenogenetic ladybug

Wolbachia is a bacterial endosymbiont that is primarily transmitted from mother to offspring. To increase their transmission, some strains manipulate their hosts reproduction to favor female offspring, such as by inducing parthenogenesis. Here, we assess whether Wolbachia induces parthenogenesis in recently discovered parthenogenetic populations of the ladybug Nephus voeltzkowi by treating females with an antibiotic. Females from sexual populations, which we show are not infected by Wolbachia, serve as a control. Our results demonstrate that the treatment decreases Wolbachia load, subsequently reducing egg production and development among parthenogenetic females, while having no effect on sexual females. Wolbachia load and reproduction then rebound when the treatment is removed. This suggests that the Wolbachia infection is necessary for successful reproduction in the parthenogenetic females, and it may play a two-part role by facilitating egg laying and late embryo development. The cooccurrence of Wolbachia infection and parthenogenesis in N. voeltzkowi, as well as Wolbachias manipulation of host reproduction makes a likely candidate of Wolbachia-induced parthenogenesis outside of haplo-diploids. Understanding how Wolbachia can impact diverse insect reproductive systems can shed a light on the extent in which these bacteria can manipulate hosts for their own gain.