EPG Recordings Reveal Differential Feeding Behaviors in Sogatella furcifera in Response to Plant Virus Infection and Transmission Success.

Plant viruses are primarily transmitted by insect vectors and virus infection may influence on the vectors' feeding behaviors. Using an electrical penetration graph, we detected that infection with the Southern rice black-streaked dwarf virus (SRBSDV) in the white-backed planthopper (WBPH) and in rice plants both altered the vector's feeding behavior. When viruliferous WBPH (carrying SRBSDV) were fed on uninfected plants, they spent more time in salivation and phloem sap ingestion than non-viruliferous insects. In comparison with uninfected plants, infected plants showed an arrestant effect on non-viruliferous WBPH for phloem sap ingestion. Differential feeding behaviors were also detected between the WBPH that inoculated or acquired SRBSDV and those that failed to. The WBPH that inoculated SRBSDV exhibited more probing bouts, salivation events and phloem sap ingestion events and longer salivation than those that failed to. The WBPH that acquired SRBSDV were quicker to reach phloem and spent more time in phloem sap ingestion than those that failed to. These behavior alterations in the vector may have adaptive advantages for SRBSDV transmission and spread success because greater salivation by viruliferous vectors on uninfected hosts will promote virus inoculation, whereas more sap ingestion by non-viruliferous vectors on infected hosts will promote virus acquisition.