Citrus leprosis

Citrus leprosis is a significant viral disease affecting citrus crops, caused by viruses belonging to the genus Cilevirus. This pathogen causes localized lesions on leaves, stems, and fruits. It is considered one of the most economically damaging diseases in regions where citrus production is intensive and mite populations are uncontrolled.

The disease primarily impacts various species within the Citrus genus, causing premature abscission of leaves and fruits. In severe cases, the infection can cause dieback of twigs and branches, eventually leading to a general decline in tree health and productivity. The economic impact is felt through both yield loss and the reduced marketability of infected fruits.

Symptoms are distinct and often serve as the primary diagnostic tool. Affected tissues show chlorotic or necrotic spots, often arranged in rings or concentric patterns. When the virus infects fruit, it creates corky lesions that ruin the appearance of the peel, making the fruit unacceptable for fresh consumption and international export markets.

The transmission of the virus is exclusively mediated by false spider mites from the genus Brevipalpus. These mites acquire the virus while feeding on infected plant tissue and transmit it to healthy plants during subsequent feeding sessions. The spread of the disease is strictly dependent on the movement and colonization patterns of these vectors within the orchard.

Integrated pest management (IPM) is the most effective approach to mitigate the risks associated with this virus. The strategy focuses on suppressing the mite vector population through:

• Routine scouting of foliage to detect early-stage mite infestations.
• Strategic application of acaricides to reduce the vector population below economic thresholds.
• Pruning and destroying heavily infected tree components to reduce viral inoculum.
• Implementing strict quarantine measures to prevent the spread of infected nursery stock.