A bothersome plant virus first discovered in 2006 in the Salinas Valley of California was discovered last season near Tacna, Ariz., a farming community east of Yuma, and in five different fields in California's Imperial Valley. Scientists still do not know how INSV found its way to Arizona. Researchers with the University of Arizona, including Stephanie Slinski, a plant pathologist, and the associate director of the Yuma Center of Excellence for Desert Agriculture, continue to seek answers.