Parthenogenetically reproducing aphid colonies of R. padi were maintained on CYDV-RPV infected or healthy caged oats at 20uC with an 18-h photo-period for 21 days. Aphids were harvested from plants for protein extraction as described [77] . Proteins were extracted from aphids using the TCA-Acetone method as described [77] . The pellets were dried and stored at 280uC until used for mass spectrometry, approximately 2 weeks.