Myrtle rust infection may threaten native plants in city
A myrtle rust infection has been found in Hamilton and there are concerns it will threaten one of the city’s last stands of ancient forest.
Ministry for Primary Industries (MPI) could not confirm the yellow powdery fungus found on ramarama shrubs in the suburb of Riverlea was myrtle rust yesterday.
However, on the day, specialist tree removers wearing boiler suits and respirators removed six of the infected native plants – lophomyrtus – from a property and another plant from a neighbouring property on the same street.
Two men sprayed the infected plants with a solution, cut branches away one by one, and carefully bagged them in plastic and a canvas bag the size of a wool fadge.
The property owner, who did not want to be named, spotted the myrtle rust, a fungal disease, last Tuesday and called the MPI hotline.
‘‘I do a lot of work down at Hammond Park planting trees and I love my trees and look at them, water and say gidday to them, so I noticed them pretty quickly,’’ he said. ‘‘An ordinary person who doesn’t look at their trees probably doesn’t notice, you know?’’
He’s grateful to have found the myrtle rust but it’s a worry having it in the city. He stocks seeds from native trees at the nearby Hammond Bush and has planted more than 200 trees in the past few years.
‘‘If that’s the only case around in Hamilton and they can contain it, then that’s good.’’
Hammond Bush, a 1-hectare stand of swamp maire, ra¯ta¯ and ma¯nuka is less than 500m away from the affected area.
The MPI website says myrtle rust has the potential to seriously affect myrtle species including natives like po¯ hutukawa, ramarama, ma¯nuka, ra¯ta¯ and swamp maire. Ramarama and po¯ hutukawa are most affected.
Andrea Graves, who lives nearby and helps at the Riverlea Environment Society working bees in Hammond Bush, is concerned.
‘‘The big concern is if it spreads to the swamp maire at Hammond Bush,’’ Graves said.
‘‘It’s such a biodiverse area. Those swamp maire are so precious and they are mature and they are the backbone of the ecosystem.’’
Originally from Australia, the wind-blown fungus made its way across the Tasman Sea and was first found in New Zealand at a Kerikeri nursery in May 2017.
It then spread to Taranaki, Bay of Plenty, Waikato, Auckland and Wellington.
It affects feijoa, guavas and monkey apples but the ma¯nuka honey industry could be in the clear. Its effect on Australia’s ma¯ nuka honey industry has been insignificant, MPI said.
‘‘We have working bees in there on the last Saturday of every month so we will have to think about holding off.
‘‘Should people not be taking tools down there because we’re cutting invasive vines … that kind of transfer risk. We’re hoping to get some advice,’’ Graves said.
‘‘Bug Man’’ Ruud Kleinpaste, who worked with MPI to educate the public about myrtle rust, said it was always going to spread around the country no matter what.
‘‘This stuff was always going to go everywhere, wasn’t it?’’ Kleinpaste said.
‘‘If you have spores the size of smoke – think about that – how the hell do you stop it?’’
In February, MPI lifted a ban on moving myrtle plants across Taranaki after the fungus continued to spread across the region.
‘‘If the Tasman is not a barrier, the Waikato River is not a barrier.’’