Verification of mapping of the extent of Phytophthora dieback disease, based on shadowless colour aerial photography, involves the routine testing of soil and root samples collected from beneath dying, Phytophthora-sensitive native plant “indicator species” for the presence of the pathogen. In addition to P. cinnamomi, other isolates have been recovered on selective agar following the baiting of soil, or the direct plating of plant tissue, during these operations. These have been identified, using morphological characters, as P. citricola, P. megasperma, P. cryptogea, P. drechsleri, P. nicotianae, and P. boehmeriae