Infection route of rice grassy stunt virus, a tenuivirus, in the body of its brown planthopper vector, Nilaparvata lugens (Hemiptera: Delphacidae) after ingestion of virus

•Route of RGSV spread in the internal organs of its insect vector is detailed.•RGSV spreads directly from the midgut epithelium to the salivary glands of its insect vector.•Direct infection route may contribute to efficient transmission of RGSV by its insect vector.

Rice grassy stunt virus (RGSV), a tenuivirus, is transmitted by the brown planthopper (BPH), Nilaparvata lugens (Hemiptera, Delphacidae), in a persistent-propagative manner. In this study, immunofluorescence microscopy was used to investigate the infection route of RGSV in the internal organs of BPH after acquiring the virus by feeding on RGSV-infected rice plants. The sequential infection study revealed that RGSV initially infected the midgut epithelium, then crossed the basal lamina into the midgut visceral muscles, from where RGSV apparently spread into the hemolymph, then into the salivary glands of its BPH vector. The mechanism underlying this infection route of RGSV in its BPH vector may confer an advantage for the direct spread of RGSV from the initially infected epithelium to the salivary glands in BPH, contributing to efficient transmission of RGSV by its insect vector.