A plant virus first found in 2006 in the Salinas Valley of California, was discovered last season near Tacna, Arizona. This a farming community east of Yuma. It was also detected in five different fields in California's Imperial Valley. The disease causes decay and will render a lettuce crop unmarketable. It is vectored by a common insect.
Impatiens necrotic spot virus, or INSV for short, can resemble burn damage caused by chemical applications, according to Steven Koike, a plant pathologist and director of TriCal Diagnostics in Hollister, Calif. Koike was a farm advisor with the University of California when the disease was first discovered in California.
Unlike the soil borne pathogens that lead to Fusarium and other plant diseases in produce crops, INSV is vectored by the Western flower thrips. The Western flower thrips has long been a pest of concern for lettuce, spinach, and cabbage growers because of the feeding damage it left behind, according to John Palumbo, Extension entomologist with the University of Arizona. That feeding damage also leaves crops unmarketable, particularly for fresh market uses.