Project reference: 2000-01
The Economic Impact of the Monterey Pine Aphid
Project description:
Introduction
The Monterey pine aphid (Essigella californicus) is a recent immigrant to New Zealand and Australia. In New Zealand the aphid is present throughout the forestry regions of the North Island, Nelson, Canterbury and central Otago.
In Australia the Monterey pine aphid is considered to be a potentially serious pest of radiata pine (Pinus radiata) and the Australian forestry industry is working collectively across state boundaries assess the pest status of the aphid. Forest surveys in Australia have recorded varying levels of defoliation with some trees suffering 75% defoliation. Death of 10+ year old trees has also been recorded in NSW forests and a model conservatively suggests a loss of AUD$17.3 million per annum for Australasian radiata forests over 10 years old.
In New Zealand Monterey pine aphid is not considered to be a serious threat to exotic forest plantations by MAF (based on forest health surveys) and currently no work is being done in the insect. Alate (winged) Monterey pine aphids have been caught in a Hawke´s Bay suction trap throughout the current season (1999/2000). The catches peaked at over 400 aphids per week in early March (data set to end of March).
Objective
To determine the pest status of Monterey pine aphid by quantitatively assessing infestation levels of Monterey pine aphid and resulting defoliation in at least two stands of radiata pines using the standard methods developed in Australia.
Methods
Two regions: dry (= east coast) and wet (= west coast) and two sites per region will be sampled. Stands will be 10-20 years old.
Monterey pine aphid infestations and defoliation of individual trees will be sampled monthly from November to February and fortnightly through March and April when the aphid populations peak. Standard sampling methods and tree growth measurements developed and adopted by Australian forest entomologists for Monterey pine aphid, will be used.
Natural enemy populations will be monitored and any observations of predation and/or parasitism recorded. Trees infested with Monterey pine aphid will also be surveyed for fungal diseases that might be contributing to defoliation of the trees.
Collaboration
Towards this end a workshop on Monterey pine aphid was held in Melbourne in November last year which reviewed the knowledge on Monterey pine aphid. Two New Zealand entomologists attended: Tim Herman, Crop & Food Research and Clive Appleton, Forest Research. The aim of the workshop was to establish a coordinated approach across Australia (and New Zealand) to manage Monterey pine aphid and identify research priorities.
One of the priorities of the workshop was to encourage research in New Zealand and collaboration between the two countries.
As noted above this research project will use standard Australian sampling procedures for Monterey pine aphid which will allow this relatively small data set to be included in and compared to a much larger data set.
Research Provider:
Forest Research
Crop & Food Research
