Published on Wednesday, 19 April 2023 at 11:32:00 AM
The Department of Primary Industries and Regional Development (DPIRD) will be undertaking chemical treatment trials at Hyde Park from late May to stop the spread of the invasive pest Polyphagous shot-hole borer (PSHB).
Vincent has been working with DPIRD on options to treat infested trees.
About the size of a sesame seed, PSHB excavates tunnels in trees where they cultivate fungus as a food source.
This fungus spreads in the tunnels disrupting the flow of water and nutrients.
Trees damaged by PSHB can become a constant source of beetles that can disperse and impact neighbouring trees.
In time, beetle damage can cause large limbs to break and fall and, depending on the tree species, the fungus is likely to kill the tree.
DPIRD will be undertaking a chemical treatment trial on infested trees at Hyde Park on Thursday 22 June from 8am.
The current best management strategy for PSHB is pruning of infested branches or entire removal (including stump grinding) of heavily infested trees to contain the spread of PSHB and minimise further impact on neighbouring trees.
While there are no registered or chemical treatments to target PSHB in Australia, DPIRD has obtained an emergency permit from the Australian Pesticides and Veterinary Medicines Authority (APVMA) to start a chemical treatment trial for PSHB at Hyde Park.
APVMA has deemed the treatment environmentally safe when used as per label and permit.
The treatments will be administered by DPIRD scientists or licensed pest management technicians supervised by DPIRD scientists and Vincent staff.
What chemical treatment is being used?
• The treatment involves the use of an injectable form of emamectin benzoate.
• This compound is a bio-pesticide derived from Streptomyces avermitilis, a soil bacterium.
• Emamectin benzoate has been used to control another insect pest attacking London Plane trees.
• The tree injectable form of this chemical that DPIRD plan to use has been developed and formulated entirely within Australia by a 100 per cent Australian owned company.
• Independent studies have shown no detectable residues were found in buds, nectar and pollen of several eucalyptus species.
• It is environmentally safe and presents a low risk to pollinating insects such as bees when applied correctly.
• The APVMA is satisfied that when used as per label and permit, this chemical treatment presents a minimal risk to the environment.
How is it applied?
• Holes are drilled into the tree trunk to allow for the insertion of an applicator device which confines the chemical within the tree trunk.
• The chemical is injected through the plug into the drilled hole, using a syringe/applicator.
• The holes are drilled deep enough to allow the chemical to move upwards in the tree’s vascular tissue.
• Once injected, the chemical is transported by the trees vascular system.
What steps will be taken to ensure the safety of Hyde Park flora, fauna and people visiting the park?
• The chemical treatment will be applied as per the permit to ensure it presents a minimal risk to the surrounding environment.
• Work will start after the school holidays in a bid to reduce disruption to the public.
• If applicator syringes need to be left in trees, they will be left at a height that prevents contact with park visitors.
What does the emergency permit from Australian Pesticides and Veterinary Medicines Authority (APVMA) mean?
• Registration or permitting through the APVMA provides assurance that risks to human and environmental health are adequately understood and evaluated prior to use of a chemical in the Australian environment.
• This is particularly important when chemicals may be used at the urban interface such as for PSHB, where wildlife (including pollinators such as bees), waterways and humans interact very closely.
Report borer damage (or unusual pests) to DPIRD via the MyPestGuide® Reporter app or the Pest and Disease Information Service on (08) 9368 3080 or email padis@dpird.wa.gov.au.
More information is available at agric.wa.gov.au/borer
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