Polyphagous Shot Hole Borer

• To date (March 2024) there have been infestations to the west of Perry Lakes in Lake Claremont, to the south at Masons Gardens in Dalkeith, to the north at Wembley Golf Course and to the east at Floreat, Wembley and West Leederville. 
• The borer was first identified in North Fremantle September 2021. 
• It is only a matter of time before PSHB beetles get to Perry Lakes Reserve.

• London plane trees (Plantanus x acerifolia).  These are located in the central verge on Underwood Avenue immediately south of the Perry Lakes Reserve. 
• Morton Bay Fig (Ficus macrophylla) (a single tree) west of West Lake. 

These trees are easily infected and produce numerous female beetles, which can fly up to 400m to infect other trees.

Whether a tree is infested depends partly on its susceptibility, but also on the intensity of attack. 

• Native trees tend not to be affected unless under heavy attack. 
• Monitoring the status of preferred host trees is important to prevent build-up of PSHB beetle in the reserve. If infested, these trees will almost certainly need to be removed.

There are three reproductive host tree species in the reserve or in nearby Bold Park.

• Casuarina obesa (Swamp sheoak)
• Corymbia callophylla (Marri)
• Melaleuca rhaphiophylla (Swamp paperbark)

Infestation of reproductive host tree species can result in production of female beetles that infest other host species.  To date they have been removed in Perth, but it may be possible to just remove infected branches.

There are four non-reproductive host tree species in the reserve.

• Agonis flexuosa (Willow myrtle or peppermint)
• Eucalyptus gomphocephala (Tuart)
• Eucalyptus rudis (Flooded gum)
• Acacia saligna(Orange or Yellow wattle). 

These trees can become infested with PSHB but breeding galleries are not established and trees are not expected to die.

Flooded gums are the main tree in the reserve, being in a parkland setting, often with turf underneath. A reduction in canopy of these trees would greatly impact the nature conservation values in the reserve. 

• Removed in Perth.  It may be possible to remove just infected branches.
• There is no spray or chemical currently registered for use in Australia to combat the insect or fungus, although systemic insecticides are used in other parts of the world with limited results because the fungus blocks the flow of fluids inside the tree.
• Early management, especially of preferred host trees, will be encouraged to lessen the risk of infestation of other trees in the reserve. 

• The Friends of Perry Lakes and Town of Cambridge will raise awareness of the risk of PSHB infestation of trees and enlist Citizen Scientists to inspect and report any possible infestations. People can inspect the trunks of trees, fallen branches or use binoculars. 
• Awareness will be made through our Newsletter and Information Boards located around the lakes. People will be encouraged to download and use the MyPestGuideTMReporter app. 
• Early management.

• Department of Department of Primary Industries and Regional Development website
• List of PSHB host plants (updated periodically)
• Town of Cambridge website