Long-Term Management for Gum Leaf Skeletoniser MothMonday, Jun 16, 2003
The Ministry of Agriculture and Forestry has decided to adopt a long-term management approach, rather than eradication, to control the gum leaf skeletoniser moth in Auckland, MAF's Director Forest Biosecurity Peter Thomson said today.
The moth was first discovered in August 2001 at one site in Onehunga, which was immediately treated. Monitoring of that site and the surrounding area continued without further detections. Subsequent surveillance early this year resulted in a large number of infested sites being identified throughout South Auckland.
In February MAF put in place measures to determine the full extent of the infestation, slow the spread of the pest and evaluate whether or not eradication would be feasible.
"We have now determined that eradication is not an option owing largely to the extent of the current infestation and the likely rate of spread of the pest," Mr Thomson said.
Gum leaf skeletoniser has been detected across approximately 25,000 hectares of Auckland, from Devonport to the north, to Wiri and Auckland Airport in the south. Unlike the painted apple moth, the gum leaf skeletoniser female moth can fly up to two kilometres and is capable of laying eggs in several locations.
MAF convened a group of industry and technical experts to provide advice on gum leaf skeletoniser and the feasibility of eradication. The group determined that eradication would require a combination of widespread removal of host trees and aerial spraying for a period of two years. However, the chances of successfully eradicating the pest were considered to be low and long-term management was seen as a more realistic option.
"Any eradication effort over such a large urban area is extremely challenging and while eradication might initially have been MAF's preferred option it would be unwise to pursue it with such a low probability of success, "said Mr Thomson.
As an alternative to eradication, MAF will consider options for assisting commercial growers, councils and other stakeholders in the transition to long term management of gum leaf skeletoniser. This support may include ongoing work to slow the moth's spread, research into biological control agents and research into effective control measures such as spraying options for commercial plantations. MAF will work with interested stakeholders to determine the exact nature of what is necessary for this transitional support, and seek Cabinet approval for a package of measures.