Dutch elm disease trapping season starts

6 November 1998

Determination of the Ministry of Agriculture and Forestry staff to rid New Zealand of Dutch elm disease looks to be paying off. No new sites of infection were found in Auckland last year and its hoped that the 1998/99 summer trapping season, about to start, will yield the same results.

Trapping for the insect vector, the elm bark beetle (Scolytus multistriatus) which can carry the fungus Ophiostoma novo-ulmi began this week. MAF contractors will be deploying traps throughout the four cities of Auckland and parts of Papakura and Rodney Districts.

Last year only one infected elm was found and destroyed after three extensive surveys of approximately 18,500 elms in Auckland.

For ten years Ministry staff have been fighting Dutch elm disease, and Forest Health national manager, Ross Morgan, says the campaign is working. However, measures remain in place to prevent the disease spreading. Elm material cannot be moved into, out or around much of the Auckland region (the four Auckland cities and part of Papakura). Mr Morgan says that effectively this means no elm species may be planted within the area.

Elm material like firewood should not be stored, and if pruning elms, the branches should be clipped on site or if taken to the tip, buried on request. Mr Morgan also asks people removing whole elm trees to inform the Forest Health Advisor at MAF in Auckland so that the tree can be deleted from the elm tree database.

He says the Government responded swiftly to the Dutch elm disease threat, first found in Auckland during the 1989/90 summer. Since then an average of $300,000 a year has been invested in the eradication programme. Local councils in the affected areas have also made significant contributions towards meeting the cost of combatting the disease.

Mr Morgan warns against underestimating the potential impact of the disease in New Zealand. He says most of Auckland’s elms would die within five years if the eradication programme was abandoned. Overseas the disease has wiped out the elm population throughout the United Kingdom, Europe and parts of North America.

Visible signs of the disease are wilting branches with curled yellow and brown leaves falling from the tree prematurely. The fungus can spread from a single branch to cover the entire tree within one to two weeks.

For further information contact:

Ross Morgan, National Manager Forest Health, ph: 0800 765 000 or mobile: 025 938 149

Contact MPI

for general enquiries phone

0800 00 83 33