Citrus leprosis-N disease causes symptoms on leaves, fruit and twigs (green bark). The viruses are transmitted by Brevipalpus spp. (flat mites). These viruses are of the lifetime circulative type inside the mite, and the mite can transmit the virus once it has acquired the virus through feeding on infected plant tissue. The virus is not systemic in the host plant. The disease is controlled by controlling the mite vectors, as well as removal of inoculum sources (symptomatic citrus tissue as well as alternative hosts).
The disease, Citrus leprosis is caused by different types of RNA viruses, commonly referred to as either the cytoplasmic type (CL-C) belonging either to the Cilevirus of Higrevirus genus or the nuclear type (CL-N) belonging to the genus Dichorhavirus. Viruses of the CL-C type include Citrus leprosis Virus-C, Citrus leprosis virus-C2 and Hibiscus green spot virus.
Viruses of the CL-N type include Citrus leprosis Virus-N and Orchid fleck virus (OFV). Molecular diagnostics were used to identify the presence of a virus belonging to the Dichorhavirus genus and full-genome determination of the virus showed closest sequence identity to a Cymbidium isolate of OFV. OFV was previously found on orchids in South Africa.