Catharanthus begomovirus

Pathogen and disease type. Catharanthus begomovirus (Begomovirus catharticae) is a plant virus belonging to the Geminiviridae family. It is a persistent, aphid/whitefly-transmitted pathogen that targets the vascular system of the host plant. The virus disrupts normal cell function, leading to systemic infection and physiological stress.

Host plants. The primary host for this begomovirus is Catharanthus roseus (Madagascar periwinkle). While it shows a strong preference for this ornamental species, its host range can include related plants in the Apocynaceae family, posing a threat to both nursery production and landscape plantings.

Symptoms and signs. Typical clinical signs include interveinal chlorosis, mosaic patterns on the foliage, and severe leaf curling or distortion. Stunting is a hallmark symptom; infected plants often appear significantly dwarfed compared to healthy specimens. Floral development may be inhibited, resulting in fewer blooms and poor flower quality.

Development and spread. The virus is transmitted primarily by the whitefly Bemisia tabaci. The virus is acquired by the insect during feeding and transmitted to healthy plants. Warm, humid environments promote both whitefly proliferation and virus incubation, making greenhouse operations particularly vulnerable to rapid outbreaks of the disease.

Damage and control measures. The economic impact is primarily related to the loss of commercial quality, making plants unsellable. Since there is no cure for viral infections in plants, management focuses on prevention:

• Rigorous monitoring for whitefly populations.
• Maintaining greenhouse hygiene and weed control.
• Using certified virus-free seeds and cuttings.
• Rouging and destroying symptomatic plants immediately.
• Employing biological control agents or targeted insecticides to manage the insect vector.