Farm Forestry New Zealand
PESTS AND DISEASES OF FORESTRY IN NEW ZEALAND
New Zealand may be rid of eucalypt pest
From Biosecurity Issue 33, February 2002.
Despite two intensive surveys of host vegetation late last year, no further sign of the Australian gum leaf skeletoniser (Uraba lugens) was found in Onehunga, Auckland.
With no sign of the skeletoniser in Mt Maunganui for over a year (Biosecurity 32:15) MAF is optimistic that New Zealand may be rid of the eucalypt pest but it is too early to rest easy. Detection of any pest at low population levels is difficult and monitoring will continue at both locations for some time yet.
The Australian pest was found in August last year in Waikaraka Cemetery, Onehunga. The detection followed a discovery of the insect in Mt Maunganui four years earlier, in June 1997.
MAF’s contractor VIGIL, Forest Health Advisory Services, carried out the most recent survey in Auckland in November. To ensure the gum leaf skeletoniser is no longer present in the Onehunga area, monitoring will continue up to six times per year as part of the MAF Forest Biosecurity risk site surveillance programme.
Mark Ross, National Adviser, Forest Pest Surveillance and Response, MAF Forest Biosecurity
Gum leaf skeletoniser eradication looks promising
From Biosecurity Issue 32, December 2001.
No life stage of the Australian gum leaf skeletoniser (Uraba lugens) was found in the recent survey of the Mount Maunganui area and MAF believes eradication is a distinct possibility.
The gum leaf skeletoniser was first discovered in June 1997 on a eucalyptus tree on Mount Maunganui golf course. The insect feeds on eucalypts and can completely defoliate trees.
In early October, surveyors from VIGIL, Forest Research inspected 257 potential host trees at local golf courses, industrial sites, residential properties and reserves. Cherry pickers were used to gain access to tall trees, binoculars aided the inspection of high foliage, and sheets were spread on the ground to collect fallen insects.
Although all trees were intensively inspected, no live gum leaf skeletoniser life stages or feeding damage was found. The last discovery of live insects in the Tauranga district was over a year ago, in October 2000.
Since the last survey,se veral host trees had been removed to make way for the development of a commercial building. The felled trees were deeply buried at a local landfill and pose no further risk.
If the insect is still present in the Tauranga district it is at a very low population level, making it hard to find.
With this in mind, MAF has initiated research into the development of a sex pheromone that would attract moths to traps and assist in finding any remaining insects.
Monitoring at New Zealand’s other infestation site in Onehunga, Auckland (Biosecurity 30:8) has revealed no further sign of the pest.
Mark Ross, National Adviser, Forest Pest Surveillance and Response, MAF Forest Biosecurity
NZFFA on facebook