Rice is one of the most widely grown crops worldwide. The brown planthopper (BPH), Nilaparvata lugens Sta˚l
(Homoptera: Delphacidae), is the most serious insect pest of rice in Asia. BPH is a monophagous sucking insect
that mainly feeds on rice (Oryza sativa L.)3,4. These insects cause direct damage by sucking sap from the phloem of
susceptible rice varieties and indirect damage by transmitting viral diseases5. When the density of BPH remarkably
increases, many rice plants die and, eventually, ‘‘hopperburn’’ appears in the rice paddy. Large amounts of
insecticides are used to control BPH. However, BPH showing resistance to insecticides such as imidacloprid have
emerged6, requiring the development of other control methods as an alternative to insecticide use.