Optimal Use of Insecticide Against the Small Brown Planthopper, <i>Laodelphax striatellus</i>, Effectively Reduces the Damage Caused by Rice Stripe Virus

Rice stripe virus disease is one of the most devastating diseases of rice (<i>Oryza sativa</i>) in East Asia. The causal virus, rice stripe virus (RSV), is persistently transmitted by the small brown planthopper (<i>Laodelphax striatellus</i>, SBPH). Because there is no effective treatment once rice plants are infected with RSV, it is crucial to prevent RSV infection in rice to minimize the damage. This study evaluated the effect of SBPH control with insecticides applied to the nursery box at transplanting and/or sprayed in the field on RSV infection and yield loss. We found that insecticide application either to nursery boxes or in the field reduced the percentage of diseased plants, the magnitude of damage in diseased plants, and yield loss. The combination of nursery box and field insecticide applications was the most effective at controlling the disease as it provided seamless control of SBPH from transplanting to the initial panicle formation stage. The study results offer a detailed description of the process by which chemical control of SBPH reduces damage caused by RSV. We expect these findings to be useful in developing an integrated pest management system for RSV.