Loss of Wolbachia but not Cardinium in the invasive range of the Australian thrips species, Pezothrips kellyanus

Independent cytoplasmic incompatibility induced byCardiniumandWolbachiamaintains endosymbiont coinfections in haplodiploid thrips populations

“…Here, we have demonstrated that both Cardinium and Wolbachia induce distinct types of complete CI in the absence of other fitness effects and with high transmission rates; therefore, our findings support the previous reports of high prevalence of Cardinium and Wolbachia in field populations of P. kellyanus (Nguyen et al 2016). In the context of endosymbiont dynamic models for haplodiploid insects (Vavre et al 2000, the population dynamics parameters of Cardinium and Wolbachia obtained from laboratory populations of P. kellyanus also support the high prevalence of both endosymbionts in field populations of the native range in Australia, and high prevalence of Cardinium in field populations of the invasive range of this host species outside Australia (Nguyen et al 2016). However, some of the parameters obtained from the laboratory populations do not support our previous findings of lower prevalence of Wolbachia than Cardinium in field populations and the loss of Wolbachia from the invasive range of this host species (Nguyen et al 2016).…”

“…Independent of endosymbionts, virgin females produced only male offspring, confirming our previous observation of arrhenotoky in our Australian laboratory populations of P. kellyanus (Nguyen et al 2016); arrhenotoky has also been demonstrated for a P. kellyanus population in Crete (Varikou et al 2012). However, Cardinium and Wolbachia induced complete CI as no females were produced in incompatible crosses.…”

“…Line infection status was confirmed prior to and during the crossing experiments by Cardinium-and Wolbachiaspecific PCR (Nguyen et al 2016), and more sensitive long PCR and quantitative PCR (qPCR) (Tables S1-S4). pollen, at 20 ± 2°C, 70 ± 2% RH and 16:8 h (L:D) photoperiod (Supplementary Material).…”

“…This thrips species is a common citrus pest that originates from Australia, yet has independently established invasive populations in New Zealand and Mediterranean countries (Nguyen et al 2016). This thrips species is a common citrus pest that originates from Australia, yet has independently established invasive populations in New Zealand and Mediterranean countries (Nguyen et al 2016).…”

“…While Australian individuals are coinfected with both Cardinium and Wolbachia at a high prevalence, individuals within populations of the invasive range outside Australia only carry Cardinium. We then assessed these parameters obtained from laboratory populations together with previously collected data about infection prevalence in field populations (Nguyen et al 2016) in the context of theoretical models of endosymbiont invasion dynamics in haplodiploid (Vavre et al 2000 and coinfected hosts (Frank 1998) in order to evaluate whether our laboratory data support the infection prevalence found in native and invasive populations of this host species. Based on the high endosymbiont prevalence in native populations, and the presence of both males and females in populations of the native and invasive range, we hypothesized that both bacteria independently manipulate thrips reproduction by CI and not by thelytoky.…”