Has bio-control of willows been considered?

Category: Willows Research
Created: Wednesday, 27 February 2013 16:13
Published: Wednesday, 27 February 2013 16:13
Written by Webmaster
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Biological control of Willows:
Research into biological control for Willows has been debated by authorities since the 1990's when certain willow taxa were added to the list of Weeds of National Significance. The biggest argument against biological control has been the risk of the impact of the biological control agent on the millions of willows planted throughout south eastern Australia for erosion control. If these willows were to die on mass as a result of biological control the impacts on erosion and the quantity of dead timber added to our river systems would be substantial.
However in 2008 with continued research and reviews of willow taxa, distribution methods and distribution, there has been a refinement of willow control priorities and it is likely that biological controls that target the flowers on specific willow taxa may be investigated.

It has often been suggested that people involved in willow control are responsible for the release and spreading of Willow Saw fly in Australia. This would be illogical for someone who cares about our river systems to do, given the currently unquantifiable damage that could occur as a result. There are several ways saw fly could have arrived in Australia one way is it has been inadvertently transported in its cocoons, (either over-wintering cocoons or those produced during the growing season) attached to live or dead leaf material in shipping containers or even in clothing, camping, canoeing or fishing equipment of travellers returning from New Zealand. Another way is that they were blown across from NZ (as other insects have been) on the jet stream winds that occasionally blow east to west. As the Southern Hemisphere populations are reproducing clonely it would only take one sawfly to start a population.