The effect of virus titre on acquisition efficiency of Tomato spotted wilt virus by Frankliniella occidentalis and the effect of temperature on detectable period of the virus in dead bodies

Abstract

The acquisition efficiency of Tomato spotted wilt virus (TSWV) by Frankliniella occidentalis was examined using TSWV-infected Datura stramonium with various virus titres. TSWV quantities in leaves were measured using double antibody sandwich enzyme-linked immunosorbent assay (DAS-ELISA) and quantitative reverse transcription-polymerase chain reaction (qRT-PCR). The percentages of viruliferous F. occidentalis significantly correlated with DAS-ELISA and qRT-PCR values in the fed leaf piece. The detectable period of TSWV in viruliferous F. occidentalis adults trapped on sticky traps was also examined at various temperatures. At 25°C or less, TSWV could still be detected by DAS-ELISA in the bodies for at least 20 days after the capture of viruliferous F. occidentalis, although ELISA values had decreased gradually over time more rapidly at higher temperatures. The quantities of TSWV RNA detected by qRT-PCR rapidly decreased. The mean value decreased to half in a day, and reduced to 7.3% of the initial mean value after 14 days.