Characterising the Associated Virome and Microbiota of Asian Citrus Psyllid (Diaphorina citri) in Samoa

The Asian citrus psyllid (<i>Diaphorina citri</i>) is an economically important pest of citrus as it is a vector of the bacterium (<i>Candidatus</i> Liberibacter asiaticus, <i>C</i>Las) that causes huanglongbing disease (HLB). Understanding the virome of <i>D. citri</i> is important for uncovering factors that influence vector competence, to support biosecurity surveillance, and to identify candidate agents for biological control. Previous studies have identified several <i>D. citri</i>-associated viruses from various geographical populations of this pest. To further investigate virus diversity in this pest, high-throughput sequencing was used to analyse <i>D. citri</i> populations from the Samoan islands of Upolu and Savai'i. Eleven novel viruses from the <i>Yadokariviridae</i>, <i>Botourmiaviridae</i>, <i>Nodaviridae</i>, <i>Mymonaviridae</i>, <i>Partitiviridae</i>, <i>Totiviridae</i>, and <i>Polymycoviridae</i> were identified as well as some that corresponded to unclassified groups. In addition, microbiome analysis revealed the presence of several endosymbiotic microorganisms, including <i>Wolbachia</i>, as well as some plant pathogenic fungi, including <i>Botrytis cinerea</i>. However, the causative agent of HLB disease (<i>C</i>Las) was not detected in the RNA-Seq data. These findings highlight the complex and diverse microbiota associated with <i>D. citri</i> and suggest potential interactions and dynamics between microorganisms and psyllid-associated viruses. Further research is needed to understand the ecological significance of these discoveries, and whether the novel viruses play a role in regulating field populations of the psyllid.