Editorial: Slack response to painted apple moth a disgrace

The saga of the painted apple moth, against which aerial spraying was supposed to start in West Auckland at the weekend, has been a disgrace. It is almost three years since the forest pest appeared. In that time it has spread largely unhindered while the guardians of New Zealand's biosecurity have tiptoed around scientific experience, council rules and the hypersensitivity of a minority to pesticides.

The whole saga has been a sorry contrast to the decisive measures taken against the insect's relative, the white-spotted tussock moth, in 1996. That aerial spraying programme over areas of Auckland's eastern suburbs was not universally popular either. But the Agriculture Minister at that time, John Falloon, took a personal hand in the decision and the programme went ahead with dispatch. His successor, Jim Sutton, has been much more circumspect.

When the latest unwanted moth from Australia was first noticed in Glendene, in April 1999, the Ministry of Agriculture and Forestry responded quickly but not effectively. A chemical spraying operation failed to eradicate the moth, which feeds on not just apple plantations but appears to have acquired a taste for native trees as well. Since surviving the initial spray, the invader has turned up in other parts of Auckland, including the Waitakere Ranges, and may have reached the point that it is too late to eradicate.

That, at least, is the belief of a former HortResearch scientist who was instrumental in developing the pheromone that caught the tussock moth but who was not engaged, as a private consultant now, to produce a pheromone for the apple moth. MAF awarded the contract to a scientist at HortResearch and the ministry is still waiting for a result. It is hard to find an explanation for the ministry's preference for the crown research institute over the private consultant. Let's resist the suspicion that the prevailing political ideology has contributed to the pest's survival.

Now the ministry has had to resort to aerial spraying with a soil bacterium, Btk, which kills the moth in its caterpillar stage. Critics say that if it had used this agent in ground spraying at the outset, it might not now be obliged to bombard the residents of West Auckland from a helicopter.

Aerial spraying of urban residential areas is always unsettling. In this case, the substance does not seem significantly threatening. When it was used in the eastern suburbs there were some complaints of harm to health but an official investigation could not find a link between the ailments and the spray. Nor could it find any other cause, which is always grist to the mill of fearmongers. So is the ministry's caution in declaring that Btk is "safe for healthy people".

Nothing less than a cast-iron guarantee of harmlessness will satisfy some people. They may run far greater risks in the way they choose to live their lives, but present them with the remotest possibility of a minor respiratory irritation from a public spraying programme and there will be an outcry. The ministry has gone so far as to assemble a register of residents with health conditions that might be aggravated by the spray and all were to be contacted by a doctor before spraying began. In a more general attempt to assuage concerns the ministry set up a community advisory group that has met several times. But it feels its views have not been heeded.

The head of the ministry's eradication programme, Dr Ruth Frampton, can point to surveys of residents that show most do not share the advisory group's concerns. In the latest survey, 62 per cent of residents endorsed the proposed spraying. It is a pity, then, that it was not done long ago.

Who knows what damage the painted apple moth might do if it again escapes the ministry's clutches? If it were to infest our forestry and horticulture the economic impact has been assessed at $48 million over 20 years. It ought to have been tackled with urgency on every front as soon as it appeared. Biosecurity in a country like this cannot wait for scientific and community debate. Mr Sutton should see that this saga is never repeated.

nzherald.co.nz/environment