Factors Affecting the Strength of Cardinium-Induced Cytoplasmic Incompatibility in the Parasitic Wasp Encarsia pergandiella (Hymenoptera: Aphelinidae)

Abstract

Bacteria that cause cytoplasmic incompatibility (CI) are among the most common maternally transmitted parasites of insects. In CI, uninfected females produce few or no offspring when they mate with infected males and, as a result, are often at a reproductive disadvantage relative to infected females. Two different bacteria are known to cause CI, Wolbachia and Cardinium. CI Cardinium was discovered more recently and has been little studied. Here, factors that could influence the reduction in reproductive output in a CI cross, or CI "strength," were explored in the parasitic wasp Encarsia pergandiella. Cardinium in this wasp exhibits variable CI strength. Experiments tested the effect of male age, male size, male host species, Cardinium density, and male development time on CI strength. We found a striking effect of male development time, with males that took longer to develop exhibiting stronger CI when mated to uninfected females. Male age had little effect; although in one experiment, the oldest males exhibited stronger CI. Male size, host species, and bacterial density had no effect on the strength of CI. Identifying the factors that control CI are crucial for understanding the dynamics of infection, as well as the success of strategies that aim to use CI microbes to control insect pests and disease vectors.

A revision of the Encarsia pergandiella species complex (Hymenoptera: Aphelinidae) shows cryptic diversity in parasitoids of whitefly pests

“…Furthermore, these three species are model systems for the study of symbiotic interactions between parasitoid wasps and bacterial endosymbionts, prompting an array of biological, cytogenetic, genomic and transcriptomic investigations (e.g. Zchori‐Fein et al., , ; Kenyon & Hunter, ; Perlman et al., , ; Chiel et al., ; Harris et al., ; Penz et al., ; Mancini et al., , ). The present revision provides a stable taxonomic framework for such studies, hence increasing the appeal of this species complex for future study.…”

“…() and Perlman et al . () refer to this species. Also, the first Cardinium endosymbiont genome sequenced (Penz et al., ) is hosted by this Encarsia species, in which it induces cytoplasmic incompatibility (Perlman et al., , ).…”

“…The Texas native E. pergandiella in Gould et al (2008), Encarsia pergandiella sensu Schuster & Price (1996), Buckner et al (2000), , and Hunter et al (2003), the sexual E. pergandiella in Zchori-Fein et al (2004), Kenyon & Hunter (2007), Greenberg et al (2008), Perlman et al (2008), Chiel et al (2009), Godfray (2010, Harris et al (2010), Penz et al (2012) and Perlman et al (2014) refer to this species. Also, the first Cardinium endosymbiont genome sequenced (Penz et al, 2012) is hosted by this Encarsia species, in which it induces cytoplasmic incompatibility (Perlman et al, 2008(Perlman et al, , 2014. 14,15) Encarsia tabacivora Viggiani (1985) Diagnosis.…”

Independent cytoplasmic incompatibility induced byCardiniumandWolbachiamaintains endosymbiont coinfections in haplodiploid thrips populations

“…All these factors define the infection threshold beyond which infection frequencies in host populations will either increase (toward a stable equilibrium or fixation of infection) or decrease (toward loss of infection). The strength of Wolbachia CI can depend on the bacterial genotype (Charlat et al 2004), the host genotype (Bordenstein et al 2003), temperature (Hoffmann et al 1986;Clancy and Hoffmann 1998) and bacterial density (Breeuwer and Werren 1993;Bourtzis et al 1996;Mouton et al 2003), but less is known for Cardinium except for the reports of host developmental factors (Perlman et al 2014) and genotypic effects (Ros and Breeuwer 2009;Gebiola et al 2016b). The strength of Wolbachia CI can depend on the bacterial genotype (Charlat et al 2004), the host genotype (Bordenstein et al 2003), temperature (Hoffmann et al 1986;Clancy and Hoffmann 1998) and bacterial density (Breeuwer and Werren 1993;Bourtzis et al 1996;Mouton et al 2003), but less is known for Cardinium except for the reports of host developmental factors (Perlman et al 2014) and genotypic effects (Ros and Breeuwer 2009;Gebiola et al 2016b).…”

“Darwin's corollary” and cytoplasmic incompatibility induced by Cardinium may contribute to speciation in Encarsia wasps (Hymenoptera: Aphelinidae)

“…Cardinium causes unidirectional CI in E. suzannae ( = E. pergandiella in Johnson , Perlman et al. , ; Harris et al. ).…”