Native plants in which infection with introduced or unidentified viruses was detected by ELISA tests on samples.

For an explanation of virus acronyms see Table 1, - = Not tested, * = TuYV detected by BWYV polyclonal antibodies. ** = Tospovirus positive sample tested negative for TSWV and Impatiens necrotic spot virus (INSV), + = Native orchid collection. Samples were either tested individually or grouped (in 5′s–10′s) before testing. When sufficient grouped samples were present, percentage infection was calculated using the formula of Gibbs and Gower [71]. All orchid samples also tested for Cymbidium mosaic virus and Odontoglossum ringspot virus by ELISA, but none contained them.