Biological properties and vector competence of <i>Diaphorina citri</i> for <i>Candidatus</i> Liberibacter asiaticus modulated by an insect-specific virus.

Abstract

Insect-specific viruses (ISVs) infect only insects and have been studied primarily in mosquitoes. Here, we extend the concept of ISVs to include those found in plant-feeding insect vectors, such as <i>Diaphorina citri</i>, the vector of <i>Candidatus</i> Liberibacter asiaticus (<i>C</i>Las), the causal agent of citrus Huanglongbing. Using Diaphorina citri flavi-like virus (DcFLV) as a model, we examined its effects on host biology and <i>C</i>Las transmission. DcFLV infection delayed development and preoviposition and reduced feeding activity, whereas overall survival, oviposition, and sex ratio were unaffected. DcFLV-infected <i>D. citri</i> transmitted <i>C</i>Las with ∼20% greater efficiency than uninfected controls, despite no significant difference in <i>C</i>Las titers. These findings suggest that ISVs can modulate the transmission dynamics of plant pathogens by insect vectors, adding complexity to vector-pathogen interactions.