Occurrence of a picorna-like virus in planthopper species and its transmission in Laodelphax striatellus

Abstract

Himetobi P virus (HiPV) was detected in three planthopper species from the temperate monsson region of Japan. High incidences of infection occurred in some cultures of Laodelphax striatellus (range: 0–100%), Nilaparvata lugens (0–88%), and Sogatella furcifera (0–58%). In the field HiPV was only detected, at low incidence, in L. striatellus (0–6%). The virus was not detected in three other homopterans: Nephotettix cincticeps, Rhopalosiphum maidis, and R. padi, which feed on the Poaceae. High concentrations of HiPV were detected in adults and nymphs of L. striatellus. The virus was not detected in eggs and was not transovarially transmitted. Maternal contamination and contamination from surrounding plant tissues may be a source of inoculum for hatching L. striatellus eggs. Frass contained high concentrations of HiPV and is a likely source of inoculum. HiPV did not multiply in rice or wheat nor was it translocated from inoculated leaves to other parts of the plant. Therefore host plants form, at best, a transient reservoir of inoculum. HiPV transmission is compared with that of rice stripe tenuivirus which infects both L. striatellus and its plant hosts rice and wheat.