When comparing effects on R. padi with and without R. padi
virus (RhPV), aphid cultures with and without virus were kept in
separate rooms and precautions were taken to avoid cross-contamination.
To start an RhPV-free aphid culture, newborn nymphs were
separated and after reproduction individually tested using RT-PCR
with the method described in Ban et al. (2007). Samples were also
taken for testing of virus status during the period of the
experiment.