To evaluate the effect of a reflective net (Slimwhite®45) and timing of insecticide application on suppressing lisianthus (Eustoma grandiflorum ) necrotic ringspot disease caused by Iris yellow spot virus (IYSV), the incidences of vector thrips (Thrips tabaci ) and necrotic ringspot disease were examined in Karatsu City, Saga Prefecture, Japan in 2007. In a survey plot with reflective net, the total number of captured T. tabaci on a sticky trap outside and inside the greenhouse were lower than those without reflective net. The incidence of necrotic ringspot disease was lower when insecticide (acephate) treatments were timed with the emergence of viruliferous T. tabaci. The disease incidence was drastically reduced when the adjusted insecticide treatments and reflective net were used together.
