Council proactively protects iconic pandanus palms

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Bundaberg Regional Council’s Natural Areas team are working to save the spiky pandanus palms that line many of Bundaberg’s beaches, from a tiny pest.

The pandanus leaf hopper Jamella australiae is native to northern Queensland where its population is kept in check by a native micro wasp Aphanomerus r. Pusillus.

The leafhopper is believed to have been accidentally transported to southern Queensland and after feeding on the sap of pandanus can breed to high infestation levels quickly causing dieback.

Visual signs of dieback include black sooty mould on the leaves and trunk of the trees. In turn this can result in fungal pathogens causing the decline and death of new growth, and eventually the whole tree.

Dieback is occurring across central and South East Queensland, northern New South Wales and has been the cause of community concern in and around Bundaberg.

The Natural Areas team have been monitoring and treating pandanus along the Woongarra coastline for the past few years, and recently engaged a pandanus expert to undertake a dieback survey across the coastal foreshore.

The survey provided the team with the current status of the pandanus population and highlights where work is required to reduce plant decline.

Natural Areas Officer Sally Obst said that pandanus play a vital role in the stabilisation of sand dunes due to their spreading root systems, so any loss was of concern due to increased erosion, loss of shade and also loss of habitat for animals.

“Our team have undertaken specialised training on how to identify the leafhoppers and treat affected pandanus.”

“We are using the wasps as a biological control and are finding this method very successful as the wasp parasitises the eggs of the leafhopper helping to control the leafhopper population,” Sally said.

“Sites where wasps have been released are monitored to assess the need for follow up treatment.”

“In addition to biological control the team are also focusing efforts on ‘leaf stripping,’ which involves removing infested and rotting leaves from the crown.”

“The use of pesticides has proved effective if other preventative works have not succeeded but are only considered in certain circumstances.”

03082020 Pandanus Dieback Workshop 01
Pandanus Dieback Specialist Joel Fostin working with Bundaberg Regional Council to help save the coastal Pandanus tree.

Expert advice leads fight against leafhopper

The Natural Areas team have organised for further training this month to be delivered to staff from Council’s Parks Operations and Maintenance team to increase the knowledge base of staff who can contribute to providing appropriate treatment.

Sally said that following training, staff will be able to identify leafhopper outbreaks, assess infestation levels, discover how to translocate wasp eggs to pandanus, learn the techniques of leaf stripping and how best to encourage pandanus regeneration.

“The Natural Areas team will continue to undertake twice yearly monitoring of pandanus with a long-term aim to improve the resilience of Pandanus along our coastline.”

“We’ll keep working with the experts to ensure we’re best prepared to protect this significant species.”