The Central American garden escapee Mist flower, currently the most widely spread plant pest in the north is coming
under attack from an introduced Jamaican fungus.
Mist flower and the related Mexican devil weed grow prolifically in Northland due to our warm moist climate. As do many
other Central and South American plant species.
Fortunately these conditions are also conducive to the spread of the fungus. Mist flower forms dense mats over large
areas especially streamsides, cliff faces, native and exotic forests and agricultural land.
The biological control agent (the mist flower fungus or white smut - Entyloma ageratinae) was released in a joint
operation between Regional Councils, Landcare Research and the Department of Conservation, at the end of 1998 after
rigorous testing to ensure that it was safe to release into our environments.
The fungus will be followed up by the release of a gall fly which will further attack the weakened plants. Currently the
gall fly is still in quarantine in Hawaii, where it has undergone trials to ensure that it will not effect any other
species. Both species have been found to be effective in Hawaii, where over 52,000 hectares of Mist flower infested land
was rehabilitated.
The Mist flower was released in 9 sites in Northland, Auckland and the Waikato. In the Auckland region the fungus has
been found up to 14km away from the release sites. There was good news for Northland when Department of Conservation
Rangers from the Kerikeri Area office recently found the fungus on Mist flower plants up to 27 kilometers from the
nearest release site in south Puketi.
It is hoped that the decline of the Mistflower population will lead to the revival of more desired species throughout
the region.
Other plants that have been identified as potential targets for biological control in Northland are banana passionfruit,
wild ginger, gorse, ragwort, scotch thistle, broom and tobacco weed.
Any enquiry’s to Dan or Claire at the Department of Conservation Kerikeri
@ 09 407 8474 or Ken Massey of the Northland Regional Council @ 09 438 4639.