Farm Forestry New Zealand
PESTS AND DISEASES OF FORESTRY IN NEW ZEALAND
Eucalypt problems
Scion is the leading provider of forest-related knowledge in New Zealand
Formerly known as the Forest Research Institute, Scion has been a leader in research relating to forest health for over 50 years. The Rotorua-based Crown Research Institute continues to provide science that will protect all forests from damage caused by insect pests, pathogens and weeds. The information presented below arises from these research activities.
Forest Health News 82, February 1999.
In Wellington (city) the population and associated damage of Gonipterus scutellatus has usually far outweighed that of any other foliage insect. This year I have also noted a marked increase in the numbers of Paropsis charybdis . On some of the eucalypts sampled they were almost equal in number to the Gonipterus weevils. In the Hutt and Wainuiomata valleys I have noted many eucalypts, predominantly ashes and eastern blue gums ( E. grandis, E. botryoides, E. saligna), having significant branch, leader or whole tree failure. As foliage is often still attached to the branches and much of the branch tissue is still green, it appears that death has been fast. In the case of the some of the ashes I have noted some kino ring formation and extensive investigation revealed small wounds consistent with Platypus attack. The eastern blue gums and the rest of the ashes are more puzzling as drainage, aspect etc. do not correlate with dieback (although in a few areas there has been some flooding and wet feet will take its toll). Depressions in bark were always apparent on the branches and necrotic tissue, and from which a species of Cytospora was consistently isolated. Australian research has suggested that this fungus is a "pioneer invader" associated with damaged sapwood and that weather can play a role? Wellington always has a measure of top failure etc. associated with the high winds (wind thrash and foliage loss) and this may be a contributing factor.
(Brent Rogan, MAF)
This information is intended for general interest only. It is not intended to be a substitute for specific specialist advice on any matter and should not be relied on for that purpose. Scion will not be liable for any direct, indirect, incidental, special, consequential or exemplary damages, loss of profits, or any other intangible losses that result from using the information provided on this site.
(Scion is the trading name of the New Zealand Forest Research Institute Limited.)
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