Brett Summerell from Sydney’s Royal Botanic Garden has recently returned from a trip to South Africa where he saw the devastation caused by polyphagous shot-hole borer, a new pest in Australia. He gave this firsthand account on LinkedIn.
“Whilst I was in South Africa recently I got the chance to see the impact of Polyphagous Shot-Hole Borer on a range of tree species in Johannesburg and Pretoria. This tiny beetle attacks the tree boring into the stem and branches carrying Fusarium fungi with it on specialised structures called mycangia. Once in the tree the fungus spreads through the tree further debilitating the tree – often leading to its death. It is estimated that this combination of the beetle and fungus will lead to the death of up to 40% of the urban tree population in Johannesburg – perhaps as many as 4 million trees!
“One of the tree species affected there are plane trees – which are of course one of the most frequently planted trees in the Sydney urban tree population. Now that the beetle is in Perth it is probably only a matter of time before it gets to the east coast.
“While Plane trees may not be everyone’s favourite tree, especially if you are suffering from allergies to them, they play an important role in mitigating extreme temperatures in the urban environment – it is critical that we keep this beetle and its fungus out of Sydney as long as possible. It is also important to ensure that new plantings of urban trees take into account susceptibility to this.
“I have attached a few photos of the typical damage to Acer negundo and Platanus species – keep an eye for this! Keep thing to look out for are the tiny holes indicating the beetle has penetrated the tree trunk.”
More information
Brett Summerell is Chief Scientist and Director of Science, Education and Conservation at the Australian Institute of Botanical Science, Royal Botanic Gardens and Domain Trust.
Here’s a link to Brett’s original post on Linkedin:
Here’s a link to our recent alert on polyphagous shot-hole borer:
