Eucalyptus Trees Attract Australian Pests
Friday 6 September 2002
Eucalyptus Trees At Auckland Airport Attract Australian Pests
Two Australian psyllids, an aphid-like pest which causes damage to certain eucalypt trees, have been detected for the first time on the surrounds of Auckland Airport.
The insects were detected as part of routine risk site inspections by MAF. One of the psyllids (Creiis lituratus) is a known pest species in Australia where it causes significant damage to some commercial eucalyptus species.
"At this stage we have completed our initial survey around a 5 kilometre radius of the first interception," said Peter Thomson, Director of MAF Forest Biosecurity. "The conclusion of our technical advisory group is that the species has become locally established and eradication is not an option. In any case, available sprays have limited efficacy and are not suitable for use in urban areas. Living as they do under a protective cover, these insects are difficult to reach with chemicals."
"Severe infestations can result in extensive damage to foliage. We are certain that these pests damage eucalypt trees only, and we are now investigating the species of eucalypts they are likely to prefer as hosts here. There is some evidence that these pests have arrived complete with their own natural parasite and this could provide us with a means of biological control," said Mr Thomson. An information sheet on the psyllids - C. lituratus and Anoeconeoassa communis - will be published for circulated to plant nurseries, wood lot owners and local government biosecurity officers to assist them with localised management.
Technical advisory group member Denis Hocking, of the Farm Forestry Association, said it is unfortunate some of the trees that surround our seaports and airports, especially some of the eucalypts, provide convenient "pest motels". "Australia is our nearest neighbour and host material and pests from there regularly cross the Tasman. One of our options might be to remove the large, inaccessible eucalypt trees in these high risk zones and replace them with trees that aren't attractive to pests, or perhaps low-growing varieties that are easier to inspect and can provide a more effective buffer. This could be combined with improved landscape and amenity values," said Mr Hocking.
MAF Forest Biosecurity surveys the surrounds of Auckland Airport for exotic pests seven times a year. The frequency of surveillance was recently increased from five to seven times, in recognition of the potential number of interceptions.