Epidemiology of a re-emerging thrips-transmitted virus affecting lettuce production in the Salinas Valley of California

Western flower thrips, Frankliniella occidentalis, is the primary insect vector for impatiens necrotic spot virus (INSV), a re-emerging pathogen that affects lettuce in the Salinas Valley. Although INSV was first described in the region in 2008, it wasn’t until 2018 when the virus began causing substantial economic losses to the lettuce industry. Only limited control tactics exist for thrips management in lettuce and there are no direct methods for managing INSV. Furthermore, the large host range of plant species that can support thrips populations and INSV creates a need to understand the epidemiology of the vector and virus. Here, we report on various research objectives to understand the population dynamics of thrips and the occurrence of INSV in lettuce agroecosystems. These studies provide knowledge that are leading to new strategies to improve the management of thrips and INSV in the Salinas Valley of California.