Dialogue: Too little, too late in war to eradicate apple moth

Spraying to rid West Auckland of the painted apple moth is due to start on Saturday. MERIEL WATTS* says it may be too late, so badly has the programme been handled.

The painted apple moth is an Australian that appears to have hitchhiked across the Tasman Sea on a container ship. It was identified in April 1999 in Glendene, West Auckland. Then it turned up on the other side of Auckland, in Mt Wellington.

The Ministry of Agriculture and Forestry Machine swung into action and began a low-key, but chemical intensive, eradication programme. But the moth is still with us in West Auckland two years later.

Even worse, recent data from the ministry's moth-trapping programme indicate it has spread well beyond its original infestation and is to be found in the ecologically significant Waitakere Ranges, as well as areas such as Greenlane and Onehunga.

Information released in December revealed that some native trees, as well as apples, are favoured food for the moth. It is not a severe problem in Australia, probably because it exists in some sort of ecological balance with predators, parasites and diseases and it gets sprayed with insecticides in orchards. But it could pose problems for our organic orchards and native ecology.

Why has it all gone so badly wrong? Two fundamental reasons: the ministry refused to learn the lessons from the successful eradication of the white-spotted tussock moth in East Auckland; and it resorted to chemical pesticides instead of the soil bacterium Btk.

Politics were involved in these decisions. The ministry gave the job of moth extermination to Dr Ruth Frampton. She failed, until recently, to involve members of the tussock moth team, including Dr John Clearwater, whose international colleagues successfully identified and synthesised the female sex attractant (pheromone) that was so crucial to that programme's success. The pheromone is used in traps to catch male moths and delineate the area of infestation.

Instead, Dr Frampton gave the pheromone contract to HortResearch which, two years later, has still not come up with the crucial pheromone product. Finally, after political pressure, Dr Clearwater's team was recently provided with the material to identify the pheromone and is quickly achieving success.

Meanwhile, the ministry, having rejected the highly effective and relatively safe Btk, was spraying infestations of the moth with chlorpyrifos. Chlorpyrifos is a toxic organophosphate insecticide that was severely restricted in the United States in 2000 because of significant health effects, including foetal brain damage.

Yet last May the ministry's official external reviewers of the moth programme, Drs Leibhold and Simpson, described chlorpyrifos as having "little or no known effects on mammals". Our Environmental Risk Management Authority has placed chlorpyrifos fifth on the list of high-priority chemicals to be reassessed because of the US information.

The ministry is now using Decis, or deltamethrin, a synthetic pyrethroid with less drastic human health effects. But, unlike Btk, Decis is highly toxic to aquatic life, so it cannot be sprayed along the Whau Creek and other riparian margins, where the moth caterpillars are multiplying.

Now this pest is spreading out of control and the ministry is having to resort to aerial spraying with Btk, amid mounting community concern. It would not be in this position if it had used Btk from the start in its ground-spraying operations.

There is considerable community opposition in West Auckland to the ministry's plans to use a helicopter to spray selected areas with the Foray 48 formulation of Btk, because of reported health effects when this was used in East Auckland.

While the official public health investigation into these effects did not establish a link with the spray, neither could it explain what caused them. The sheer volume of anecdotal evidence lends credence to the view that some people are likely to get ill from exposure to Foray 48B.

How many? There is no answer. But an investigation is under way into a reported cluster of thyroid dysfunction in the spray zone in East Auckland. Foray 48B is the safest insecticide that could be used, but that safety is only relative, not absolute. Even the ministry is careful in its wording when describing Btk: "Btk is safe for healthy people".

The fiasco continued. Late last year, the ministry discovered that Waitakere City planning rules forbade low-flying helicopters without a consent. It was reported that the Minister of Agriculture, Jim Sutton, wanted to declare the moth an emergency under the Biosecurity Act, so planning laws could be overruled.

But the next day, Mr Sutton said he had not declared an emergency. Back to the council table. But not for long. On December 11, Mr Sutton announced the spraying programme would be exempted from the provisions of the Resource Management Act under section 7a of the Biosecurity Act. This means that Waitakere's planning rules can be overridden without an emergency being declared.

Meanwhile, frustration is mounting in the community. The ministry set up a community advisory group, and has met this group a number of times. But it appears to regard the group simply as a means to fulfil its obligation to consult.

The community wants the moth gone, but it does not want the health of its members or its environment compromised. The advisory group has been inventive in proposing alternative methods to the ministry, including testing a non-toxic biodynamic peppering method.

A proposal for a trial has been produced by Hanafiah Blackmore, of Society Targeting Overuse of Pesticides, and the ministry has agreed to consider it. But it has not provided the detailed data on where moths are being trapped - essential for determining where the trial should be carried out.

The ministry has refused to respond to requests to stop using Decis and replace it with Btk. It says residents can ask the ministry not to use Decis if they are concerned about health effects but fails to extend this right to neighbours who get drifted upon.

The saga continues. The ministry continues to spray Decis at will where caterpillars are found. It continues to ignore the request for information from the advisory group. The community is getting increasingly angry. And the pest continues its inexorable spread.

It is possible that the only thing that will get rid of it now is a DC-6 zooming across the skies of Auckland, dropping its load of Foray 48B. But that also may be too late - the moth may have spread out of control.

* Dr Meriel Watts is director of the Soil and Health Association.