Causal Agent:
Tomato Spotted Wilt Virus (TSWV) 
Several strains have been reported.

Vector:
Thrips (Thrips tabaci and Frankliniella species)

Distribution:
Worldwide

Symptoms:
The first visible symptom is small, orangish-yellow flecks on the older leaves. Later the leaves develop small, dark, more or less circular spots which gives them a bronzed appearance. The growing tips of the leaves may die as the disease progresses. Dark, shiny streaks are often seen along the stem and petioles. Severely infected plants are stunted with yellowish drooping foliage which imparts a wilting appearance to the plant. Fruit usually show characteristic green, yellow and red, slightly raised concentric rings, although some strains can cause severe necrosis.

Conditions for Disease Development:
This virus has a very wide host range from which it can be transmitted in a persistent manner by thrips. Although the virus is acquired at the larval stage it is only spread by the adults which are wind-blown to tomatoes from infected weeds or ornamental plants. Usually there is very little spread within a tomato crop.

Control:
Elimination of thrips and host weeds through insecticide and herbicide applications is important for disease control. Resistant varieties should be used when possible.

Foliage yellowing and wilting            Necrotic tent lesions.
symptoms.

Yellowing and bronzing leaf symptoms.        Yellow chlorolic rings on
                                                                                the fruit.

White concentric rings         Deformed fruit with diffuse rings.
on the fruit.