Eustoma ringspot virus

The causative agent of the disease is Orthotospovirus eustomae, a viral pathogen belonging to the Tospoviridae family. It is a highly systemic virus that interferes with the plant’s cellular metabolism, leading to tissue damage and general physiological decline.

The primary host for this virus is Eustoma (Lisianthus), though it has been identified in a variety of other ornamental and agricultural crops. In greenhouse environments, the virus can spread rapidly due to high plant density, often leading to total crop failure if left unmanaged.

Diagnostic symptoms include ringspot patterns on foliage, leaf distortion, vein chlorosis, and the formation of necrotic streaks. Infected plants often exhibit stunted growth, wilting, and reduced flower production, which significantly impacts their commercial value and overall health.

The transmission of the virus is primarily mediated by thrips, particularly the Western flower thrips (Frankliniella occidentalis). The virus is acquired by the insect during feeding and can be transmitted to healthy plants throughout the lifespan of the vector, making early detection of the insect population critical.

Management and prevention focus on breaking the disease cycle through integrated pest management (IPM):

• Rigorous monitoring for thrips populations using blue or yellow sticky cards.
• Immediate removal and disposal of symptomatic plants to prevent further spread.
• Application of appropriate insecticides to control vector populations.
• Maintenance of strict sanitation protocols for tools, benches, and workers within the facility.