Big spray targets western suburbs

By ANNE BESTON, Environmental Reporter

Secret documents show the Ministry of Agriculture and Forestry plans to spray almost every suburb in West Auckland if initial efforts to eradicate a moth pest fail.

Cabinet papers obtained by the Herald say the ministry has a contingency plan to spray 9000ha in West Auckland for painted apple moth.

This is 15 times the size of the target area already made public.

The cabinet finance, infrastructure and environment committee documents say the bigger programme would cost $20 million.

The ministry is to report to the Government by February if the smaller, $11 million helicopter spraying campaign, due to start next month, does not eradicate the pest.

The papers also reveal that the ministry is spending almost $1 million on a campaign to convince West Aucklanders that spraying Btk, an organic insecticide, is necessary.

The chemical was used successfully to spray eastern suburbs for spotted tussock moth in 1996 in Operation Evergreen.

The ministry announced last month that it planned to aerial spray 300ha near Waikumete Cemetery and Traherne Island in the upper Waitemata Harbour after a trapping programme failed to eradicate the painted apple moth.

The spray campaign was due to start this month but was deferred until next month.

And it may be further delayed because the Civil Aviation Authority has not approved MAF's plans.

The cabinet papers say the approved option involves 600ha, although the first step will be the smaller area, which will affect about 800 mainly residential properties.

A senior scientist involved in the Operation Evergreen spraying says he is "one hundred per cent certain" that the ministry will have to use its fallback plan.

"The programme they have outlined so far is destined to fail," said Dr John Clearwater, a former HortResearch scientist who now runs his own company.

He said that MAF's trapping programme for painted apple moth was flawed, and re-infestation after the helicopter spraying was certain.

That meant a blanket spray campaign like the one in the eastern suburbs would have to be put into effect.

MAF staff faced a barrage of questions at a fiery meeting in New Lynn two days ago when they explained their plans to worried residents. About 200 people attended.

The chairman of the community committee that represents resident's concerns and liaises with MAF over the eradication programme, Kubi Witten-Hannah, said he also wanted to know why the ministry could not change its mind about aerial spraying now a synthetic sex attractant for the moth was about to be produced.

Associate Biosecurity Minister Marian Hobbs faced questions in Parliament over HortResearch's two-year effort to produce the sex lure for the painted apple moth.

It is a pheromone that attracts male moths, and a spotted tussock moth version was widely used in baited traps in the eastern suburbs.

Ms Hobbs said that the pheromone was useful only in trapping adult moths, and insecticide spraying was needed to kill the caterpillars.

Dr Clearwater believes he is only weeks away from producing the pheromone.

But yesterday HortResearch announced it was ready to begin trials with live male moths using a synthetic pheromone.

MAF says painted apple moth could cause $48 million of damage to New Zealand's forestry and horticultural industries if it is not eradicated.