How to Manage Pests
UC Pest Management Guidelines
Impatiens Necrotic Spot
Pathogens: Impatiens necrotic spot virus (INSV) in the tospovirus group
(Reviewed 12/09, updated 12/09)
In this Guideline:
SYMPTOMS AND SIGNS
Symptoms on plants infected with Impatiens necrotic spot virus include overall yellowing (chlorosis), dead (necrotic) spots on leaves or terminal shoots, and general stunting. Fruits show chlorotic spots, red or green areas surrounded by yellow halos, and concentric rings that may become necrotic. Symptoms are similar to those caused by another tospovirus, Tomato spotted wilt virus (TSWV) (for more information on this virus, see TOMATO SPOTTED WILT).
COMMENTS ON THE DISEASE
In California, INSV is vectored primarily by western flower thrips. When nymphs acquire tospoviruses by feeding on infected plants, they will retain the ability to transmit the virus for the remainder of their lives. INSV has a host range that consists mostly of ornamentals and is not as broad as that of TSWV.
While spraying for the thrips vector will not prevent these virus diseases from occurring, growers should still attempt to manage thrips populations when possible.
UC IPM Pest Management Guidelines:
S. T. Koike, UC Cooperative Extension, Monterey County
Acknowledgment for contributions to Diseases:B. W. Falk, Plant Pathology, UC Davis