Impatiens necrotic spot

Impatiens necrotic spot is a destructive viral disease caused by the Impatiens necrotic spot virus (INSV), a member of the Tospovirus genus. It poses a significant threat to greenhouse production worldwide due to its wide host range and the severity of symptoms it induces in infected plants.

The virus affects numerous ornamental and vegetable crops, including Anemone coronaria (Ветреница), Browallia speciosa, Slipper Flower (Calceolaria), Campanula carpatica, Sweet Pepper, Clerodendrum thomsonae, Cyclamen persicum, and Exacum affine.

Primary symptoms include chlorotic or necrotic ringspots, mosaic patterns on leaves, stunted growth, and necrotic streaks on stems. In severe cases, the plant may exhibit systemic wilting or tip necrosis, which drastically reduces the commercial value of ornamental flowers and crop yields.

The virus is primarily transmitted by the western flower thrips (Frankliniella occidentalis). Thrips acquire the virus by feeding on infected plant tissue during their larval stage; once infected, they remain carriers for the rest of their lifespan, facilitating rapid transmission within the greenhouse environment.

Management focuses on early detection and prevention. Key strategies include using virus-indexed propagation material, implementing rigorous thrips monitoring with yellow or blue sticky traps, removing symptomatic plants immediately, and applying integrated pest management (IPM) to suppress vector populations.