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The endosymbiont Wolbachia is known for manipulating host reproduction. Wolbachia also can affect host fitness by mediating interactions between plant and herbivores. However, it remains unclear whether saliva proteins are involved in this process.We found that Wolbachia infection decreased the number of deposited eggs but increased the egg hatching rate in the spider mite Tetranychus urticae Koch (Acari: Tetranychidae), a cosmopolitan pest that infects1000 species of plants. Transcriptomic and proteomic analyses revealed that Wolbachia-infected mites upregulated the gene expression levels of many T. urticae salivary proteins including a cluster of Tetranychidae-specific, functionally uncharacterized SHOT1s (secreted host-responsive proteins of Tetranychidae). The SHOT1 genes were expressed more in the feeding stages (nymphs and adults) of mites than in eggs and highly enriched in the proterosomas. RNA interference experiments showed that knockdown of SHOT1s significantly decreased Wolbachia density, increased the number of deposited eggs and decreased the egg hatching rate.Together, these results indicate that SHOT1s are positively correlated with Wolbachia density and account for Wolbachia-mediated phenotypes. Our results provide new evidence that herbivore salivary proteins are related to Wolbachia-mediated manipulations of host performance on plants. © 2022 Society of Chemical Industry.

BACKGROUND Drosophila suzukii (Matsumura, 1931) (spotted wing drosophila), an invasive species, has recently become a significant global pest of soft-skinned fruits such as berries. Unlike other Drosophila species, female D. suzukii have evolved a specialized sharp, serrated ovipositor that pierces and penetrates ripe and ripening fruits, causing them to lose commercial value and preventing their sale. A first step for the development of biological control agents for pest management may be achieved through the identification of microbes infectious for D. suzukii in the wild. RESULTS We first determined that D. suzukii is susceptible to chemicals commonly used to rear Drosophilids in the laboratory and established a diet able to sustain healthy D. suzukii growth. Using this diet, we demonstrated that of 25 species of culturable bacteria and fungi isolated from field-collected D. suzukii, eight microbes decreased host survival when injected. Three of the eight bacteria (Alcaligenes faecalis, Achromobacter spanius and Serratia marcescens) were acutely pathogenic to both D. suzukii and Drosophila melanogaster adults by injection. Feeding of these bacteria resulted in susceptibility only in larvae. CONCLUSION We successfully identified multiple microbes from field-collected D. suzukii that are pathogenic to both larvae and adults through different routes of infection, some of which could be candidates for biocontrol of this species. © 2020 Society of Chemical Industry.

BACKGROUND The whitefly Bemisia tabaci (Gennadius) is considered one of the main pests for agriculture. One important problem with the whitefly is its notorious status as a vector for plant viruses, primarily begomoviruses. We have previously identified a defensin-like antimicrobial peptide, Btdef, from the whitefly B. tabaci MEAM1. However, the function of Btdef in the immune system of the insect vector and begomovirus transmission has yet to be explored. RESULTS To explore the role of Btdef during begomovirus transmission, we firstly investigated the transcriptional response of Btdef following acquisition of Tomato yellow leaf curl China virus (TYLCCNV). The expression of Btdef was up-regulated in the viruliferous whiteflies. After RNA silencing of the Btdef gene in adult whiteflies fed with dsRNA, they were allowed to feed on TYLCCNV-infected plants and then quantified for TYLCCNV DNA titre. Unexpectedly, silencing the Btdef gene reduced both the abundance and expressions of TYLCCNV genes in the whiteflies. In the meantime, the density of the endosymbiont Rickettsia was significantly reduced in dsBtdef-fed whiteflies. CONCLUSION Our data provide evidence that Btdef is involved in begomovirus infection, possibly through symbiont-mediated alteration of begomovirus–whitefly interactions. These findings indicate that Btdef may be targeted for the development of new technology for the control of whitefly-transmitted begomoviruses. © 2016 Society of Chemical Industry

The whitefly Bemisia tabaci (Gennadius) is considered one of the main pests for agriculture. One important problem with the whitefly is its notorious status as a vector for plant viruses, primarily begomoviruses. We have previously identified a defensin-like antimicrobial peptide, Btdef, from the whitefly B. tabaci MEAM1. However, the function of Btdef in the immune system of the insect vector and begomovirus transmission has yet to be explored.To explore the role of Btdef during begomovirus transmission, we firstly investigated the transcriptional response of Btdef following acquisition of Tomato yellow leaf curl China virus (TYLCCNV). The expression of Btdef was up-regulated in the viruliferous whiteflies. After RNA silencing of the Btdef gene in adult whiteflies fed with dsRNA, they were allowed to feed on TYLCCNV-infected plants and then quantified for TYLCCNV DNA titre. Unexpectedly, silencing the Btdef gene reduced both the abundance and expressions of TYLCCNV genes in the whiteflies. In the meantime, the density of the endosymbiont Rickettsia was significantly reduced in dsBtdef-fed whiteflies.Our data provide evidence that Btdef is involved in begomovirus infection, possibly through symbiont-mediated alteration of begomovirus-whitefly interactions. These findings indicate that Btdef may be targeted for the development of new technology for the control of whitefly-transmitted begomoviruses. © 2016 Society of Chemical Industry.