Myrtle Rust in Tasmania

Myrtle rust pustules on Mewlaleuca quinquinervia (Photo L. Morin, CSIRO)

Myrtle rust pustules on Melaleuca quinquinervia (Photo L. Morin, CSIRO)

Myrtle Rust, caused by Puccinia psidii s.l. has been detected in Tasmania, Australia.  Also known as Guava or Eucalypt rust, this pathogen has an extremely wide host range, focused on the Myrtaceae.  There have been a number of pest risk analyses prepared and published by our members.  One of these indicated that parts of Tasmania are climatically suitable for P. psidii to establish, and much of the remainder is suitable for infection and growth during summer.  So far the pathogen has been detected in two focal zones (one in an area modelled suitable for establishment), and one further south in an area modelled as suitable only during favourable seasons.  Time will tell if the pest risk modelling was accurate.