Wolbachiaboth aids and hampers the performance of spider mites on different host plants

Abstract

KeywordsArthropod-plant-symbiont interaction, bacterial symbiont, fitness effects, host-plant use, mutualism, parasitism. Abstract 1In the last decades, many studies had revealed the potential role of arthropod bacterial 2 endosymbionts in shaping the host range of generalist herbivores and their performance on different 3 host plants, which, in turn, might affect endosymbiont distribution in herbivores populations. We 4 tested this by measuring the prevalence of endosymbionts in natural populations of the generalist 5 spider mite Tetranychus urticae on different host plants. Focusing on Wolbachia, we then analysed 6 how symbionts affected mite life-history traits on the same host-plants in the laboratory. Overall, the 7 prevalences of Cardinium and Rickettsia were low, whereas that of Wolbachia was high, with the 8 highest values on bean and eggplant and the lowest on purple, tomato and zuchini. Although most 9 mite life-history traits were affected by the plant species only, Wolbachia infection was detrimental 10 for egg hatching rate on purple and zucchini, and led to a more female-biased sex ratio on purple and 11 eggplant. These results suggest that endosymbionts may affect the host range of polyphagous12 herbivores, both by aiding and hampering their performance, depending on the host plant and on 13 the life-history trait that affects performance the most. Conversely, endosymbiont spread may be14 facilitated or hindered by the plants on which infected herbivores occur.15 42 (Hackett et al., 2013), and anti-herbivory defences (Barr et al., 2010, Su et al., 2015. Conversely, 43 symbiont-mediated decreased host performance on particular plants might be due to the nutrient 44 profile (e.g., specific amino acids and nitrogen content) of these plants, which promotes deleterious 45 symbiont traits and disturbs the host control over bacterial abundance (Wilkinson et al., 2007, 46 Chandler et al., 2008.

Endosymbiont diversity in natural populations of Tetranychus mites is rapidly lost under laboratory conditions

“…urticae populations, conducted two years later in the same region in Portugal, shows that the prevalence of the three endosymbionts remained relatively similar (Zélé et al, 2018b). Diversity and polymorphism thus seem stable in field populations.…”

A change in the bacterial community of spider mites decreases fecundity on multiple host plants

“…Spider mites host a large community of symbiotic bacteria, including facultative endosymbionts such as Wolbachia , Rickettsia , Cardinium, and Spiroplasma (Chaisiri, McGARRY, Morand, & Makepeace, ; Zélé, Santos, Olivieri, et al, ; Zhang, Chen, Yang, Qiao, & Hong, ), which manipulate host reproduction via various phenotypic effects (Engelstädter & Hurst, ; Moran, McCutcheon, & Nakabachi, ; Werren, Baldo, & Clark, ). Host plants that lower Wolbachia prevalence in natural T. urticae populations may also lower egg hatchability (Zélé, Santos, Godinho, & Magalhães, ), pointing to the potential for three‐way interactions between microbes, plants, and spider mites.…”

The microbiota in spider mite feces potentially reflects intestinal bacterial communities in the host

“…urticae, T. phaselus, T. kanzawai, and T. ludeni (Zhang et al, 2016;Zélé et al, 2018b;Zhu et al, 2018). This facultative endosymbiont influences host reproduction via several ways (Engelstädter & Hurst, 2009;Zélé et al, 2018a). In addition to reproductive endosymbionts, Pantoea, Enterobacter, and Pseudomonas were detected in spider mites.…”

“…The five Tetranychus species, T. truncatus (Tt), T. urticae (Tu), T. phaselus (Tp), T. kanzawai (Tk), and T. ludeni (Tl), were detected (Table 1). For the experiment, adult female spider mites with a similar age (0-3 days old) obtained from an egg-wave as described previously were used (Zélé et al, 2018a).…”