Moth spray zone likely to expand

By ANNE BESTON

Just three days before the start of aerial spraying to eradicate a moth pest, biosecurity authorities are struggling to finalise the target zone.

At yesterday's final meeting of technical experts and scientists before the operation begins, the Ministry of Agriculture and Forestry was still deciding on the final boundary of the spray zone.

However, the weather forecast means the helicopter spraying scheduled for Saturday may not go ahead anyway.

Although the infestation has been mainly linked to West Auckland, the pest has been found in Pt Chevalier and Waterview, and those suburbs look certain to be included in the operation.

The ministry's spokeswoman on the eradication project, Mary-Ann Crawford, said it was likely that just the seaward edges of both suburbs would be sprayed. They would be excluded this Saturday because residents must be given three weeks' notice.

The ministry has already targeted 560ha for spraying, excluding Pt Chevalier and Waterview. The Government has agreed to a maximum 600ha for this campaign.

If the ministry wants to spray more than that, it will have to go to the cabinet for more than the $11 million allocated to eradicate a pest considered a threat to the horticultural and forestry industries.

The ministry will review its operation after three complete sprays. Ideally, that would be in nine weeks, but Auckland's fickle weather will play a key role in the plan.

The ministry's operations manager on the project, Don Hammond, doubted that spraying would begin on Saturday, saying the forecast did not look good.

To be effective, the aerial operation needs calm, dry conditions and at least five hours of dry weather after a spray. Winds must be less than 12 km/h.

The Herald understands that at yesterday's technical advisory group meeting, opinion remained divided on whether this operation would succeed.

A significant number of the 15-member group believe that after three sprays the ministry will have to go to the Government for permission to blitz the moth over a far wider area.

The worst infestations centre around Waikumete Cemetery, Traherne Island in the upper Waitemata Harbour and the margins of the Whau River.

Meanwhile, plans are under way to move a group of horses belonging to a West Auckland riding club so they are not spooked by the low-flying BK-117 helicopter.

The Hepburn Road Riding Club in Glendene has 13 horses grazing over about 8ha bordering the Whau River, and Ms Crawford said the department would offer to help move them.

The same problem occurred when East Auckland was sprayed by a DC-6 in 1996 to eradicate the white spotted tussock moth.

Early morning motorists are being warned not to take their eyes off the road if they spot the helicopter in the upper Waitemata Harbour area. It is most likely to be seen near the Rosebank Rd motorway interchange.

The ministry suggests motorists wind up their windows if the helicopter is close by, but the sticky Btk spray will wash off in rain or water.

For further information call MAF's free line, 0800 96 96 96.

Feature: Conservation & Environment