Abstract: RT-PCR was used to detect rice stripe virus (RSV) in single viruliferous planthoppers (Laodelphax striatellus) and in infected rice plants. A 540 bp product was specifically amplified, and its content was higher in artificially feeding insects than in naturally infected insects in the rice field. Western blot analysis revealed two protein bands, of 20.7 and 19.7 kDa, detectable from individual planthoppers by use of polyclonal antiserum against S protein (s tripe disease-specific protein). The DIBA (dot immunobinding assay ) method is fast and simple to use in the detection of RSV antigen in single insects but has lower sensitivity and specificity than both RT-PCR and Western blot analysis. Possible explanations were discussed for the difference in proportion of RSV in L. striatellus found with use of these methods.