Asian gypsy moth adds to MAF's woes

By ANNE BESTON environment reporter

A 50-strong team of biosecurity staff has descended on a Hamilton suburb as the Ministry of Agriculture and Forestry goes on high alert for yet another moth pest.

A live Asian gypsy moth, considered one of the world's major forestry pests and a relative of the target of MAF's $90 million West Auckland aerial spray programme, the painted apple moth, has been found in a trap in a light industrial area of Frankton.

The pest is considered such a risk to New Zealand's native and exotic forestry and horticulture that MAF has had an early warning system of 1066 baited traps from Whangarei to Bluff since 1993. This is the first time a moth has been caught.

MAF director of forest biosecurity, Peter Thomson, said a vegetation movement restriction of up to 100km around the find was being considered but it was too early to say what the eradication options were.

"This is a serious enough pest that we will pull out all the stops and get everyone in place quickly," he said. "We hope we have got it really early, the aim is to kick this thing in the guts before it even has a chance to take hold."

MAF is fighting exotic moth invaders on three other fronts: the gumleaf skeletoniser in South Auckland, the fall webworm in the Auckland suburb of Mt Wellington and West Auckland's painted apple moth.

MAF response manager for Asian gypsy moth, Mark Ross, said it was likely the male moth had hatched from an egg mass and staff had begun a ground search for larvae in a 750m radius of the trap.

The Asian gypsy moth (Lymantria dispar) feeds on about 500 tree and plant species but is partial to poplar, willow and oak. It devastated oak forests in North America but its likely effect on New Zealand's native or exotic forests is unknown.

The moth will eat pinus radiata but trials in the 1990s suggested it did not eat totara or beech. It probably got into the country in imported used cars or Machinery.

Unlike painted apple moth, Asian gypsy moth is a long-range flyer with the male able to cover 100km and the female 20km.

That could be MAF's biggest problem in eradicating the pest, said Forest and Bird biosecurity spokesman Geoff Keey.

"If it became established it could spread relatively quickly. It's a big unknown what natives it might eat but we don't want to find that out the hard way."

The gypsy moth

* High populations of Asian gypsy moth in the US have stripped foliage off 5 million hectares of forest in one season

* The leaf-munching caterpillar feeds on more than 500 tree and plant species

* The male can fly up to 100km, the female up to 20km

* Its preferred host range includes poplars, willow and oaks but it will eat conifers, including pinus radiata, and fruit trees

* The female lays egg masses of between 300 and 1000 eggs

* Caterpillars are hairy with red and blue spots

* The Foray 48B or Btk spray being used against painted apple moth in West Auckland has been used against Asian gypsy moth in the US