The spotted wilt virus is transmitted from plant to plant by several species of a small insect called a thrip. Thrips are less than one-quarter inch in length, light green to brown, and are extremely difficult to find on the plants. Several weedy hosts and ornamental plants may serve as alternate hosts for the virus. Virus diseases cannot be controlled once the plant is infected. Therefore, every effort should be made to prevent introduction of virus diseases into the garden.
Sanitation is the primary means of controlling virus diseases.
Infected plants should be removed immediately to prevent spread of the pathogens. Perennial weeds, which may serve as alternate hosts, should be controlled in and adjacent to the garden. Avoid planting tomatoes next to peppers, or other vegetables and flowers susceptible to these diseases. Control of insects, especially thrips, will help reduce the likelihood of spotted wilt. Wilt and Virus Diseases of Tomato.