An insect virus differentially alters gene expression among life stages of an insect vector and enhances bacterial phytopathogen transmission

Huanglongbing (HLB), caused by fastidious bacteria from three <i>Candidatus</i> Liberibacter species, is the most damaging disease impacting the citrus industry worldwide. Spread by the Asian citrus psyllid (<i>Diaphorina citri</i>) in Asia and the Americas, HLB causes substantial financial losses, and has reduced citrus production in Florida by more than 90%. Although there are ongoing efforts to limit spread of the disease, effective HLB management remains elusive. Suppressing vector populations and decreasing CLas transmission are the two strategies that need to be urgently improved. Recently, a <i>D. citri</i> flavi-like virus (DcFLV) was characterized within its <i>D. citri</i> host, and it co-occurs intracellularly with CLas in psyllid populations. Here, we show that viruliferous nymphs exhibit higher CLas acquisition than non-viruliferous nymphs. Furthermore, both viruliferous adults and nymphs exhibit increased CLas transmission efficiency. We suggest the possibility of manipulating DcFLV in <i>D. citri</i> populations to reduce CLas transmission for HLB disease management.