Impatiens necrotic spot virus

Impatiens necrotic spot virus (INSV) is a destructive plant pathogen within the Orthotospovirus genus. It is considered one of the most economically significant viruses affecting greenhouse ornamental and vegetable crops globally due to its wide host range and efficiency of transmission.

The virus infects hundreds of plant species, including popular ornamentals such as impatiens, begonias, petunias, and gloxinias. It also impacts vegetable crops like tomatoes and peppers, causing significant yield losses and reducing the quality of plant products in professional horticulture.

Symptoms of an INSV infection are highly variable, often manifesting as necrotic rings, spots, chlorotic patterns, and stunting. Advanced stages of the disease usually include wilting, stem necrosis, and general plant decline, which are often mistaken for fungal or physiological disorders by growers.

The virus is transmitted primarily by several species of thrips, with the Western flower thrips (Frankliniella occidentalis) being the most prominent vector. The insects acquire the virus during their larval stages, and once infected, they are capable of transmitting the pathogen for the remainder of their adult life.

Management requires a robust integrated pest management (IPM) strategy. Key practices include monitoring thrips populations, strict sanitation, removing infected plants immediately, and controlling weed hosts that may harbor the virus. Chemical control of vectors is essential to limit the spread within the greenhouse.