Tomato spotted wilt virus

Pathogen and disease type. Tomato spotted wilt virus (TSWV) is the type species of the genus Orthotospovirus. It is a persistent, systemic pathogen that affects the overall health of the plant by disrupting metabolic processes, leading to significant physiological stress and structural necrosis.

Susceptible crops. This virus has one of the broadest host ranges of any plant virus, infecting over 1,000 plant species. It causes severe economic losses in vegetables such as tomatoes, peppers, potatoes, and various ornamental plants, making it a critical threat to both greenhouse and field-grown horticulture.

Symptoms and signs of infection. Clinical signs typically include stunted growth, chlorotic or necrotic spots, ring-shaped lesions on foliage, and distorted leaves. As the infection progresses, severe necrosis of terminal buds and stems occurs, often resulting in a characteristic «wilted» appearance of the plant tips.

Conditions for development and spread. Transmission is facilitated exclusively by thrips, particularly the Western flower thrips (Frankliniella occidentalis). The virus is acquired by larvae feeding on infected tissue and remains in the insect for its entire lifespan. Warm, dry weather encourages rapid thrips migration and virus dissemination.

Harmfulness and prevention. The virus can cause 100% crop loss in susceptible varieties. Effective management requires a combination of strategies:

• planting resistant or tolerant cultivars;
• rigorous thrips population monitoring using yellow or blue sticky traps;
• maintaining a weed-free environment;
• applying biological and chemical control against vector insects.