The risk of a Painted Apple Moth infestation in the Waikato from Auckland compost dumped at the Horotiu landfill is low, according to project director Ian Gear.
He told this week’s Environment Waikato Biosecurity Committee meeting that a protocol had been drawn up on moving vegetation from infected sites at West Auckland to Horotiu, and MAF had looked at the risks. The material – massive amounts of vegetation removed by MAF – was treated, shredded and treated again before being moved to the Waikato and an audit undertaken.
There had been no catches in Waikato traps which had been placed in March. The eradication programme appeared to be a success and as each day went by MAF was even more happy with what it was seeing. MAF would not be making the same mistakes in the Waikato that had been made in the Auckland programme, he said.
In March last year 996 male moths were caught in Auckland traps compared with nine this March. In recent months MAF had been releasing sterile male moths as a supplementary tool to the ground and aerial spray programmes. These resulted in sterile egg masses, where only a few moths would hatch.
“We should see the effects on the population in late spring but we won’t know whether the final collapse is due to the spray programme or sterile male moths.”
He said one frustration was the inability to isolate components of the moth pheromone. Work was being done in both New Zealand and Canada but the components had not been found. This meant the 1650 traps in Auckland and 30 in the Waikato had to be baited with virgin female moths at least once a week.
“We believe we are in a position to reduce the area of spray and over the coming months we will be putting up a review paper to Cabinet making recommendations for the future.”
Mr Gear said the finding of pests such as the Asian Gypsy Moth, Fall Web Worm and Gum Leaf Skeletoniser were indications that the early warning system worked rather than failed.
“For 10 years we have had traps out in high risk areas for the Asian Gypsy Moth. The web worm was found by someone noticing a liquidamber tree being eaten. Four million people have a role to play here. Now we wait and we will know if we’ve got more of a problem than one moth.”
Environment Waikato is co-ordinating a survey to determine the extent of a naturally introduced Guava Moth invasion. It will be laying traps and checking them over a 12-week period, but is concerned that no national response had been developed.
MAF says an incursion response was not feasible as the spread was too advanced and it was naturally introduced.