We have previously demonstrated that infection with the R.
padi virus (RhPV) is common in Swedish populations of R. padi
(Ban et al., 2007). Aphids with this virus infection have a shorter
life span and lower population growth (D’Arcy et al., 1981). It
was thus of interest to investigate whether the effect of thiamine
treatments of barley versus R. padi would be different, depending
on the health status of aphids. The life span and fecundity of healthy and RhPV-infected aphids were studied on control and thiamine There was no effect of thiamine
treatments on the number of days between birth and onset of
reproduction. The total life span was not affected in healthy aphids,
but it was shorter in RhPV-infected aphids
treated plants