21 June 2006
Ensis scientists have confirmed the presence of gumleaf skeletoniser (Uraba lugens) at Katikati, Bay of Plenty, marking a southward movement of the tree pest from the Auckland region.
The male moth was discovered in a pheromone trap that had been set as part of a monitoring exercise by Environment Bay of Plenty.
The gumleaf skeletoniser is an Australian moth that causes damage mainly to gum (eucalypt) trees by eating the
foliage.
The caterpillars are covered with hairs that can cause itching or rashes on skin if touched, so people handling affected plants should wear protective clothing.
Ensis Forest Biosecurity and Protection scientist, Dr Darren Kriticos says that the spread of this insect will have long term implications mainly for hardwood growers, due to loss of productivity caused by defoliation.
Local authorities also need to be aware of the pest due to the prevalence of gum trees on public land.
“Since its arrival in Auckland four years ago, the gumleaf skeletoniser has spread throughout the greater Auckland region, causing damage to gum trees and other susceptible species in city parks.
“Ensis has identified a range of chemical control options for tree growers who are concerned about defoliation,” Dr Kriticos explains.
The Ministry of Agriculture and Forestry succeeded in eradicating this pest when it first arrived in Tauranga in 1992, but subsequent eradication efforts in Auckland were unsuccessful.
Dr Kriticos applauds the work funded largely by Biosecurity New Zealand to determine the best ways of managing the pest, including chemical and biological control options.
“Over the past few years we have accumulated a lot of knowledge about the gumleaf skeletoniser and its likely impact in New Zealand.
“This groundwork provides the information required by forest growers and local authorities to manage the pest.”
Risk analysis carried out by Ensis has shown that the gumleaf skeletoniser has the potential to spread throughout New Zealand, wherever eucalypt trees are able to grow.
The pest has also been intercepted in a pheromone trap near Warkworth, confirming that gumleaf skeletoniser has moved outside the Auckland region in both directions.
Ensis Forest Biosecurity and Protection have an ongoing research programme on gumleaf skeletoniser, which includes investigating biological control options for the pest.
Information on gumleaf skeletoniser is available on the Biosecurity New Zealand website: www.biosecurity.govt.nz
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