Rice stripe virus, transmitted by the small brown planthopper Laodelphax striatellus, has recently reemerged as a major disease in Zhejiang province, eastern China. Intensive surveys during 2003 to 2006 demonstrated how the disease has spread rapidly from the northern to central and eastern regions with increasing incidence each year. In bioassays, the highest proportions of viruliferous vectors were from regions where the disease was most severe. The greatest disease incidence was in the earliest sown plants, and substantial control could be achieved by delaying planting from late May to mid-June. In experiments where different proportions of infected plants were established (by inoculation or varying the sowing date), average yield losses were 0.8% for every 1% increase in disease incidence. In inoculation experiments, young seedlings, particularly those at the three- to five-leaf stage, were the most susceptible, whereas ≤1% of plants inoculated at or after the elongation stage developed symptoms. Recent epidemics appear to have resulted from large populations of viruliferous vectors colonizing rice seedlings at the most susceptible stage. This is probably because of changes in cropping practice, recent warmer winters in Zhejiang province, and the development of resistance or tolerance to the insecticides widely used (triazophos, synthetic pyrethroids, and Imidacloprid).

The complete genome sequence of the four RNAs of rice stripe virus Zhejiang isolate was determined. In addition to polymerase modules, the pc1 protein encoded on RNA1 harbours an ovarian tumour (OTU) - like cysteine protease signature near its N-terminus, suggesting that the protein might yield the viral polymerase and one or more additional proteins by autoproteolytic cleavage and/or have deubiquitination activity. A novel inverted repeat sequence motif was found to be universal within the intergenic regions of ambisense genome segments of tenuiviruses, supporting the possibility that it may be functionally important, perhaps in regulating transcription termination.